I. Kiến thức liên quan
II. Tổng hợp topic Environment (Biology, Agriculture,...) IELTS READING (PDF)
1. Bài 1
Zoo conservation programmes
One of London Zoo’s recent advertisements caused me some irritation, so patently did it distort reality. Headlined “Without zoos, you might as well tell these animals to get stuffed”, it was bordered with illustrations of several endangered species and went on to extol the myth that without zoos like London Zoo these animals “will almost certainly disappear forever”. With the zoo world’s rather mediocre record on conservation, one might be forgiven for being slightly sceptical about such an advertisement.
Zoos were originally created as places of entertainment, and their suggested involvement with conservation didn’t seriously arise until about 30 years ago, when the Zoological Society of London held the first formal international meeting on the subject. Eight years later, a series of world conferences took place, entitled “The Breeding of Endangered Species”, and from this point onwards conservation became the zoo community’s buzzword. This commitment has now been clear defined in The World Zoo Conservation Strategy (WZCS, September 1993), which although an important and welcome document does seem to be based on an unrealistic optimism about the nature of the zoo industry.
The WZCS estimates that there are about 10,000 zoos in the world, of which around 1,000 represent a core of quality collections capable of participating in coordinated conservation programmes. This is probably the document’s first failing, as I believe that 10,000 is a serious underestimate of the total number of places masquerading as zoological establishments. Of course, it is difficult to get accurate data but, to put the issue into perspective, I have found that, in a year of working in Eastern Europe, I discover fresh zoos on almost a weekly basis.
The second flaw in the reasoning of the WZCS document is the naive faith it places in its 1,000 core zoos. One would assume that the calibre of these institutions would have been carefully examined, but it appears that the criterion for inclusion on this select list might merely be that the zoo is a member of a zoo federation or association. This might be a good starting point, working on the premise that members must meet certain standards, but again the facts don’t support the theory. The greatly respected American Association of Zoological Parks and Aquariums (AAZPA) has had extremely dubious members, and in the UK the Federation of Zoological Gardens of Great Britain and Ireland has
Occasionally had members that have been roundly censured in the national press. These include Robin Hill Adventure Park on the Isle of Wight, which many considered the most notorious collection of animals in the country. This establishment, which for years was protected by the Isle’s local council (which viewed it as a tourist amenity), was finally closed down following a damning report by a veterinary inspector appointed under the terms of the Zoo Licensing Act 1981. As it was always a collection of dubious repute, one is obliged to reflect upon the standards that the Zoo Federation sets when granting membership. The situation is even worse in developing countries where little money is available for redevelopment and it is hard to see a way of incorporating collections into the overall scheme of the WZCS.
Even assuming that the WZCS’s 1,000 core zoos are all of a high standard complete with scientific staff and research facilities, trained and dedicated keepers, accommodation that permits normal or natural behaviour, and a policy of co-operating fully with one another what might be the potential for conservation? Colin Tudge, author of Last Animals at the Zoo (Oxford University Press, 1992), argues that “if the world”s zoos worked together in co-operative breeding programmes, then even without further expansion they could save around 2,000 species of endangered land vertebrates’. This seems an extremely optimistic proposition from a man who must be aware of the failings and weaknesses of the zoo industry the man who, when a member of the council of London Zoo, had to persuade the zoo to devote more of its activities to conservation. Moreover, where are the facts to support such optimism?
Today approximately 16 species might be said to have been “saved” by captive breeding programmes, although a number of these can hardly be looked upon as resounding successes. Beyond that, about a further 20 species are being seriously considered for zoo conservation programmes. Given that the international conference at London Zoo was held 30 years ago, this is pretty slow progress, and a long way off Tudge’s target of 2,000.
Questions 16 - 22
Do the following statements agree with the views of the writer in Reading Passage 3? In boxes 16-22, write:
Y if the statement agrees with the writer
N if the statement contradicts the writer
NG if it is impossible to say what the writer thinks about this
Example: London Zoos advertisements are poorly presented. NOT GIVEN
16. London Zoo’s advertisements are dishonest.
17. Zoos made an insignificant contribution to conservation up until 30 years ago.
18. The WZCS document is not known in Eastern Europe.
19. Zoos in the WZCS select list were carefully inspected.
20. No-one knew how the animals were being treated at Robin Hill Adventure Park.
21. Colin Tudge was dissatisfied with the treatment of animals at London Zoo.
22. The number of successful zoo conservation programmes is unsatisfactory.
Choose the appropriate letters A-D and write them in boxes 23-25 on your answer sheet.
23. What were the objectives of the WZCS document?
A. to improve the calibre of zoos worldwide
B. to identify zoos suitable for conservation practice
C. to provide funds for zoos in underdeveloped countries
D. to list the endangered species of the world
24. Why does the writer refer to Robin Hill Adventure Park?
A. to support the Isle of Wight local council
B. to criticise the 1981 Zoo Licensing Act
C. to illustrate a weakness in the WZCS document
D. to exemplify the standards in AAZPA zoos
25. What word best describes the writer’s response to Colin Tudges’ prediction on captive breeding programmes?
The writer mentions a number of factors which lead him to doubt the value of the WZCS document Which THREE of the following factors are mentioned? Write your answers (A-F) in boxes 26-28 on your answer sheet.
List of Factors
A. the number of unregistered zoos in the world
B. the lack of money in developing countries
C. the actions of the Isle of Wight local council
D. the failure of the WZCS to examine the standards of the “core zoos”
E. the unrealistic aim of the WZCS in view of the number of species “saved” to date
F. the policies of WZCS zoo managers
2. Bài 2
To eke out a full-time living from their honeybees, about half the nation’s 2,000 commercial beekeepers pull up stakes each spring, migrating north to find more flowers for their bees. Besides turning floral nectar into honey, these hardworking insects also pollinate crops for farmers -for a fee. As autumn approaches, the beekeepers pack up their hives and go south, scrambling for pollination contracts in hot spots like California’s fertile Central Valley.
Of the 2,000 commercial beekeepers in the United States about half migrate This pays off in two ways Moving north in the summer and south in the winter lets bees work a longer blooming season, making more honey — money — for their keepers. Second, beekeepers can carry their hives to farmers who need bees to pollinate their crops. Every spring a migratory beekeeper in California may move up to 160 million bees to flowering fields in Minnesota and every winter his family may haul the hives back to California, where farmers will rent the bees to pollinate almond and cherry trees.
Migratory beekeeping is nothing new. The ancient Egyptians moved clay hives, probably on rafts, down the Nile to follow the bloom and nectar flow as it moved toward Cairo. In the 1880s North American beekeepers experimented with the same idea, moving bees on barges along the Mississippi and on waterways in Florida, but their lighter, wooden hives kept falling into the water. Other keepers tried the railroad and horse-drawn wagons, but that didn’t prove practical. Not until the 1920s when cars and trucks became affordable and roads improved, did migratory beekeeping begin to catch on.
For the Californian beekeeper, the pollination season begins in February. At this time, the beehives are in particular demand by farmers who have almond groves; they need two hives an acre. For the three-week long bloom, beekeepers can hire out their hives for $32 each. It’s a bonanza for the bees too. Most people consider almond honey too bitter to eat so the bees get to keep it for themselves.
By early March it is time to move the bees. It can take up to seven nights to pack the 4,000 or so hives that a beekeeper may own. These are not moved in the middle of the day because too many of the bees would end up homeless. But at night, the hives are stacked onto wooden pallets, back-to-back in sets of four, and lifted onto a truck. It is not necessary to wear gloves or a beekeeper’s veil because the hives are not being opened and the bees should remain relatively quiet. Just in case some are still lively, bees can be pacified with a few puffs of smoke blown into each hive’s narrow entrance.
In their new location, the beekeeper will pay the farmer to allow his bees to feed in such places as orange groves. The honey produced here is fragrant and sweet and can be sold by the beekeepers. To encourage the bees to produce as much honey as possible during this period, the beekeepers open the hives and stack extra boxes called supers on top. These temporary hive extensions contain frames of empty comb for the bees to fill with honey. In the brood chamber below, the bees will stash honey to eat later. To prevent the queen from crawling up to the top and laying eggs, a screen can be inserted between the brood chamber and the supers. Three weeks later the honey can be gathered.
Foul smelling chemicals are often used to irritate the bees and drive them down into the hive’s bottom boxes, leaving the honey-filled supers more or less bee free. These can then be pulled off the hive. They are heavy with honey and may weigh up to 90 pounds each. The supers are taken to a warehouse. In the extracting room, the frames are lilted out and lowered into an “uncapper” where rotating blades shave away the wax that covers each cell. The uncapped frames are put in a carousel that’s on the bottom of a large stainless steel drum. The carousel is filled to capacity with 72 frames. A switch is flipped and the frames begin to whirl at 300 revolutions per minute; centrifugal force throws the honey out of the combs. Finally, the honey is poured into barrels for shipment.
After this, approximately a quarter of the hives weakened by disease, mites, or an ageing or dead queen, will have to be replaced. To create new colonies, a healthy double hive, teeming with bees, can be separated into two boxes. One-half will hold the queen and a young, already mated queen can be put in the other half, to make two hives from one. By the time the flowers bloom, the new queens will be laying eggs, filling each hive with young worker bees. The beekeeper’s family will then migrate with them to their summer location.
Adapted from “America’s Beekeepers: Hives for Hire” by Alan Mairson, National Geographic.
The flow chart below outlines the movements of the migratory beekeeper as described in Reading Passage 126.
Complete the flow chart Choose your answers from the box at the bottom of the page and write your answers in boxes 13-19 on your answer sheet.
Label the diagram below. Choose ONE OR TWO WORDS from the Reading Passage for each answer. Write your answers in boxes 20-23 on your answer sheet.
Do the following statements agree with the information given in Reading Passage 2? In boxes 24-27, write:
YES if the statement agrees with the information given
NO if the statement contradicts the information given
NOT GIVEN if there is no information about this
24. The Egyptians keep bees on the banks of the Nile.
25. First attempts at migratory beekeeping in America were unsuccessful.
26. Bees keep honey for themselves in the bottom of the hive.
27. The honey is spun to make it liquid.
3. Bài 3
Population viability analysis
To make political decisions about the extent and type of forestry in a region it is important to understand the consequences of those decisions. One tool for assessing the impact of forestry on the ecosystem is population viability analysis (PVA). This is a tool for predicting the probability that a species will become extinct in a particular region over a specific period. It has been successfully used in the United States to provide input into resource exploitation decisions and assist wildlife managers and there is now an enormous potential for using population viability to assist wildlife management in Australia’s forests. A species becomes extinct when the last individual dies. This observation is a useful starting point for any discussion of extinction as it highlights the role of luck and chance in the extinction process. To make a prediction about extinction we need to understand the processes that can contribute to it and these fall into four broad categories which are discussed below.
A) Early attempts to predict population viability were based on demographic uncertainty whether an individual survives from one year to the next will largely be a matter of chance. Some pairs may produce several young in a single year while others may produce none in that same year. Small populations will fluctuate enormously because of the random nature of birth and death and these chance fluctuations can cause species extinctions even if, on average, the population size should increase. Taking only this uncertainty of ability to reproduce into account, extinction is unlikely if the number of individuals in a population is above about 50 and the population is growing.
B) Small populations cannot avoid a certain amount of inbreeding. This is particularly true if there is a very small number of one sex. For example, if there are only 20 individuals of a species and only one is a male, all future individuals in the species must be descended from that one male. For most animal species such individuals are less likely to survive and reproduce. Inbreeding increases the chance of extinction.
C) Variation within a species is the raw material upon which natural selection acts. Without genetic variability, a species lacks the capacity to evolve and cannot adapt to changes in its environment or to new predators and new diseases. The loss of genetic diversity associated with reductions in population size will contribute to the likelihood of extinction.
D) Recent research has shown that other factors need to be considered. Australia’s environment fluctuates enormously from year to year. These fluctuations add yet another degree of uncertainty to the survival of many species. Catastrophes such as fire, flood, drought or epidemic may reduce population sizes to a small fraction of their average level. When allowance is made for these two additional elements of uncertainty the population size necessary to be confident of persistence for a few hundred years may increase to several thousand.
Besides these processes, we need to bear in mind the distribution of a population. A species that occurs in five isolated places each containing 20 individuals will not have the same probability of extinction as a species with a single population of 100 individuals in a single locality. Where logging occurs (that is, the cutting down of forests for timber) forest-dependent creatures in that area will be forced to leave. Ground-dwelling herbivores may return within a decade. However, arboreal marsupials (that is animals which live in trees) may not recover to pre-logging densities for over a century. As more forests are logged, animal population sizes will be reduced further. Regardless of the theory or model that we choose, a reduction in population size decreases the genetic diversity of a population and increases the probability of extinction because of any or all of the processes listed above. It is, therefore, a scientific fact that increasing the area that is loaded in any region will increase the probability that forest-dependent animals will become extinct.
Do the following statements agree with the views of the writer in Part A of Reading Passage 3? In boxes 28-31 on your answer sheet, write:
YES if the statement agrees with the writer
NO if the statement contradicts the writer
NOT GIVEN if it is impossible to say what the writer thinks about this
Example: A link exists between the consequences of decisions and the decision-making process itself. Answer: YES.
28. Scientists are interested in the effect of forestry on native animals.
29. PVA has been used in Australia for many years.
30. A species is said to be extinct when only one individual exists.
31. Extinction is a naturally occurring phenomenon.
These questions are based on Part B of Reading Passage 3.
In paragraphs A to D the author describes four processes which may contribute to the extinction of a species. Match the list of processes (i-vi) to the paragraphs. Write the appropriate number (i-vi) in boxes 32-35 on your answer sheet.
NB. There are more processes than paragraphs so you will not use all of them.
32. Paragraph A
33. Paragraph B
34. Paragraph C
35. Paragraph D
i. Loss of ability to adapt
ii. Natural disasters
iii. An imbalance of the sexes
iv. Human disasters
vi. The haphazard nature of reproduction
Based on your reading of Part C, complete the sentences below with words taken from the passage. Use NO MORE THAN THREE WORDS for each answer. Write your answers in boxes 36-38 on your answer sheet.
While the population of a species may be on the increase, there is always a chance that small isolated groups .......... 36 .......... Survival of a species depends on a balance between the size of a population and its .......... 37 ......... The likelihood that animals which live in forests will become extinct is increased when .......... 38 ...........
Choose the appropriate letter A-D and write it in box 39 on your answer sheet.
39. An alternative heading for the passage could be:
A. The protection of native flora and fauna
B. Influential factors in assessing survival probability
C. An economic rationale for the logging of forests
D. Preventive measures for the extinction of a species
4. Bài 4
A. Paper is different from other waste produce because it comes from a sustainable resource: trees. Unlike the minerals and oil used to make plastics and metals, trees are replaceable. Paper is also biodegradable, so it does not pose as much threat to the environment when it is discarded. While 45 out of every 100 tonnes of wood fibre used to make paper in Australia comes from waste paper, the rest comes directly from virgin fibre from forests and plantations. By world standards, this is a good performance since the worldwide average is 33 percent waste paper. Governments have encouraged waste paper collection and sorting schemes and at the same time, the paper industry has responded by developing new recycling technologies that have paved the way for even greater utilization of used fibre. As a result, industry’s use of recycled fibres is expected to increase at twice the rate of virgin fibre over the coming years.
B. Already, waste paper constitutes 70% of paper used for packaging and advances in the technology required to remove ink from the paper have allowed a higher recycled content in newsprint and writing paper. To achieve the benefits of recycling, the community must also contribute. We need to accept a change in the quality of paper products; for example, stationery may be less white and of a rougher texture. There also needs to support from the community for waste paper collection programs. Not only do we need to make the paper available to collectors but it also needs to be separated into different types and sorted from contaminants such as staples, paperclips, string and other miscellaneous items.
C. There are technical limitations to the amount of paper which can be recycled and some paper products cannot be collected for re-use. These include paper in the form of books and permanent records, photographic paper and paper which is badly contaminated. The four most common sources of paper for recycling are factories and retail stores which gather large amounts of packaging material in which goods are delivered, also offices which have unwanted business documents and computer output, paper converters and printers and lastly households which discard newspapers and packaging material. The paper manufacturer pays a price for the paper and may also incur the collection cost.
D. Once collected, the paper has to be sorted by hand by people trained to recognise various types of paper. This is necessary because some types of paper can only be made from particular kinds of recycled fibre. The sorted paper then has to be repulped or mixed with water and broken down into its individual fibres. This mixture is called stock and may contain a wide variety of contaminating materials, particularly if it is made from mixed waste paper which has had little sorting. Various machineries are used to remove other materials from the stock. After passing through the repulping process, the fibres from printed waste paper are grey in colour because the printing ink has soaked into the individual fibres. This recycled material can only be used in products where the grey colour does not matter, such as cardboard boxes but if the grey colour is not acceptable, the fibres must be de-inked. This involves adding chemicals such as caustic soda or other alkalis, soaps and detergents, water-hardening agents such as calcium chloride, frothing agents and bleaching agents. Before the recycled fibres can be made into paper they must be refined or treated in such a way that they bond together.
E. Most paper products must contain some virgin fibre as well as recycled fibres and unlike glass, paper cannot be recycled indefinitely. Most paper is down-cycled which means that a product made from recycled paper is of an inferior quality to the original paper. Recycling paper is beneficial in that it saves some of the energy, labour and capital that go into producing virgin pulp. However, recycling requires the use of fossil fuel, a non-renewable energy source, to collect the waste paper from the community and to process it to produce new paper. And the recycling process still creates emissions which require treatment before they can be disposed of safely. Nevertheless, paper recycling is an important economical and environmental practice but one which must be carried out in a rational and viable manner for it to be useful to both industry and the community.
Questions 30 - 36
Complete the summary below of the first two paragraphs of the Reading Passage. Choose ONE OR TWO WORDS from the Reading Passage for each answer. Write your answers in boxes 30-36 on your answer sheet.
Example: From the point of view of recycling, paper has two advantages over minerals and ...........oil..........
in that firstly it comes from a resource which is ........ (30) ........ and secondly, it is less threatening to our environment when we throw it away because it is ....... (31) ...... Although Australia’s record in the re-use of waste paper is good, it is still necessary to use a combination of recycled fibre and ........ (32) ........ to make new paper. The paper industry has contributed positively and people have also been encouraged by .........(33) ......... to collect their waste on a regular basis. One major difficulty is the removal of ink from used paper but ......... (34) ......... are being made in this area. However, we need to learn to accept paper which is generally of a lower ......... (35) ......... than before and to sort our waste paper by removing ......... (36) ........ before discarding it for collection.
Questions 37 - 41
Look at paragraphs C, D, and E and, using the information in the passage, complete the flow chart below. Write your answers in boxes 37-41 on your answer sheet. Use ONE OR TWO WORDS for each answer.
5. Bài 5
It has been called the Holy Grail of modern biology. Costing more than £2 billion, it is the most ambitious scientific project since the Apollo programme that landed a man' on the moon. And it will take longer to accomplish than the lunar missions, for it will not be complete until early next century. Even before it is finished, according to those involved, this project should open up a new understanding of, and new treatments for, many of the ailments that afflict humanity. As a result of the Human Genome Project, there will be new hope of liberation from the shadows of cancer, heart disease, autoimmune diseases such as rheumatoid arthritis, and some psychiatric illnesses.
The objective of the Human Genome Project is simple to state but audacious in scope: to map and analyse every single gene within the double helix of humanity's DNA1. The project will reveal a new human anatomy - not the bones, muscles and sinews, but the complete genetic blueprint for a human being. Those working on the Human Genome Project claim that the new genetic anatomy will transform: medicine and reduce human suffering in the twenty-first century. But others see the future through a darker glass and fear that the project may open the door to a World peopled by Frankenstein's monsters and disfigured by a -new eugenics2.
The genetic inheritance a baby receives from its parents at the moment of conception fixes much of its later development, determining characteristics as varied as to whether it will have blue eyes or suffer from a life-threatening illness such as cystic fibrosis. The human genome is the compendium of all these inherited genetic instructions. Written out along the double helix of DNA are the chemical letters of the genetic text. It is an extremely long text, for the human genome contains more than 3 billion letters. On the printed page it would fill about 7,000 volumes. Yet, within little more than a decade, the position of every letter and its relation to its neighbours will have been. tracked down, analysed and recorded.
Considering how many letters there are in the human genome, nature is an excellent proof-reader. But sometimes there are mistakes. An error in a single 'word' — a gene - can give rise to the crippling condition of cystic fibrosis, the commonest genetic disorder among Caucasians. Errors in the genetic recipe for hemoglobin, the protein that gives blood its characteristic? The red colour and which carries oxygen from the lungs to the rest of the body, give rise to the most common single-gene disorder in the world: thalassaemia. More than 4,000 such single-gene defects are known to afflict humanity. The majority of them are fatal; the majority of the victims are children.
None of the single-gene disorders is a disease in the conventional sense, for which it would be possible to administer a curative drug: the defect is pre-programmed into every cell of the sufferer's body. But there is hope of progress. In 1986, American researchers identified the genetic defect underlying one type of muscular dystrophy. In 1989, a team of American and Canadian biologists announced that they had found the site of the gene which, when defective, gives rise to cystic fibrosis. Indeed, not only had they located the gene, they had analysed the sequence of letters within it and had identified the mistake' responsible for the condition. At the least, these scientific advances may offer a way of screening parents who might be at risk of transmitting a single-gene defect to any children that they conceive. Foetuses can be tested while in the womb, and if found free of the genetic defect, the parents will be relieved of worry and stress, knowing that they will be delivered of a baby free from the disorder.
In the mid-1980s, the idea gained currency within the scientific world that the techniques which were successfully deciphering disorder-related genes could be applied to a larger project: if science can learn the genetic spelling of cystic fibrosis, why not attempt to find out how to spell 'human'? Momentum quickly built up behind the Human Genome Project and its objective of 'sequencing' the entire genome — writing out all the letters in their correct order.
But the consequences of the Human Genome Project go far beyond a narrow focus on disease. Some of its supporters have made claims of great extravagance - that the Project will bring us to understand, at the most fundamental level, what it is to be human. Yet many - people are concerned that such an emphasis on humanity's genetic constitution may distort our ' sense of values, and lead us to forget that human life is more than just the expression of a genetic program written in the chemistry of DNA.
If properly applied, the new knowledge generated by the Human Genome Project may free humanity from the terrible scourge of diverse diseases. But if the new knowledge is not used wisely, it also holds the threat of creating new forms of discrimination and new methods of oppression. Many characteristics, such as height and intelligence, result not from the action of genes alone, but from subtle interactions between genes and the environment. What would be the implications if humanity were to understand, with precision, the genetic constitution which, given the same environment, will predispose one person towards a higher intelligence than another individual whose genes were differently shuffled?
Once before in this century, the relentless curiosity of scientific researchers brought to light forces of nature in the power of the atom, the mastery of which has shaped the destiny of nations and overshadowed all our lives. The Human Genome Project holds the promise that, ultimately, we may be able to alter our genetic inheritance if we so choose. But there is the central moral problem: how can we ensure that when we choose, we choose correctly? That such a potential a promise and not a threat We need only look at the past to understand the danger.
1 DNA: Deoxyribonucleic acid, molecules responsible for the transference of genetic characteristics.
2 Eugenics: The science of improving the qualities of the human race; especially the careful selection of parents.
Complete the sentences below (Questions 27-32) with words taken from Reading Passage 3. Use NO MORE THAN THREE WORDS OR A NUMBER for each answer. Write your answers in boxes 27-32 on your answer sheet.
Example: The passage compares the genetic instructions in DNA to chemical letters
27. The passage compares the Project in scale to the ..................................
28. The possible completion date of the Project is ..................................
29. To write out the human genome on paper would require .................................. books.
30. A genetic problem cannot be treated with drugs because strictly speaking it is not a ..................................
31. Research into genetic defects had its first success in the discovery of the cause of one-form of ..................................
32. The second success of research into genetic defects was to find the cause of ..................................
Classify the following statements as representing
A. the writer's fears about the Human Genome Project
B. other people's fears about the Project reported by the writer
C. the writer's reporting of facts about the Project
D. the writer's reporting of the long-term hopes for the Project
Write the appropriate letters A-D in boxes 33-40 on your answer sheet.
33. The Project will provide a new understanding of major diseases.
34. All the components which make up DNA are to be recorded and studied.
35. Genetic monsters may be created.
36. The correct order and inter-relation of all genetic data in all DNA will be mapped.
37. Parents will no longer worry about giving birth to defective offspring.
38. Being 'human' may be defined solely in terms of describable physical data.
39. People may be discriminated against in new ways.
40. From past experience-humans may not use this new knowledge wisely.
6. Bài 6
A Remarkable Beetle
Some of the most remarkable beetles are the dung beetles, which spend almost their whole lives eating and breeding in dung1.
More than 4,000 species of these remarkable creatures have evolved and adapted to the world’s different climates and the dung of its many animals. Australia’s native dung beetles are scrub and woodland dwellers, specialising in coarse marsupial droppings and avoiding the soft cattle dung in which bush flies and buffalo flies breed.
In the early 1960s George Bornemissza, then a scientist at the Australian Government’s premier research organisation, the Commonwealth Scientific and Industrial Research Organisation (CSIRO), suggested that dung beetles should be introduced to Australia to control dung-breeding flies. Between 1968 and 1982, the CSIRO imported insects from about 50 different species of dung beetle, from Asia, Europe and Africa, aiming to match them to different climatic zones in Australia. Of the 26 species that are known to have become successfully integrated into the local environment, only one, an African species released in northern Australia, has reached its natural boundary.
Introducing dung beetles into a pasture is a simple process: approximately 1,500 beetles are released, a handful at a time, into fresh cow pats2 in the cow pasture.
The beetles immediately disappear beneath the pats digging and tunnelling and, if they successfully adapt to their new environment, soon become a permanent, self sustaining part of the local ecology. In time they multiply and within three or four years the benefits to the pasture are obvious.
Dung beetles work from the inside of the pat so they are sheltered from predators such as birds and foxes. Most species burrow into the soil and bury dung in tunnels directly underneath the pats, which are hollowed out from within. Some large species originating from France excavate tunnels to a depth of approximately 30 cm below the dung pat. These beetles make sausage-shaped brood chambers along the tunnels. The shallowest tunnels belong to a much smaller Spanish species that buries dung in chambers that hang like fruit from the branches of a pear tree. South African beetles dig narrow tunnels of approximately 20 cm below the surface of the pat. Some surface-dwelling beetles, including a South African species, cut perfectly-shaped balls from the pat, which are rolled away and attached to the bases of plants.
For maximum dung burial in spring, summer and autumn, farmers require a variety of species with overlapping periods of activity. In the cooler environments of the state of Victoria, the large French species (2.5 cms long) is matched with smaller (half this size), temperate-climate Spanish species. The former are slow to recover from the winter cold and produce only one or two generations of offspring from late spring until autumn. The latter, which multiply rapidly in early spring, produce two to five generations annually. The South African ball-rolling species, being a subtropical beetle, prefers the climate of northern and coastal New South Wales where it commonly works with the South African tunnelling species. In warmer climates, many species are active for longer periods of the year.
Dung beetles were initially introduced in the late 1960s with a view to controlling buffalo flies by removing the dung within a day or two and so preventing flies from breeding. However, other benefits have become evident. Once the beetle larvae have finished pupation, the residue is a first-rate source of fertiliser. The tunnels abandoned by the beetles provide excellent aeration and water channels for root systems. In addition, when the new generation of beetles has left the nest the abandoned burrows are an attractive habitat for soil-enriching earthworms. The digested dung in these burrows is an excellent food supply for the earthworms, which decompose it further to provide essential soil nutrients. If it were not for the dung beetle, chemical fertiliser and dung would be washed by rain into streams and rivers before it could be absorbed into the hard earth, polluting water courses and causing blooms of blue-green algae. Without the beetles to dispose of the dung, cow pats would litter pastures making grass inedible to cattle and depriving the soil of sunlight. Australia’s 30 million cattle each produce 10-12 cow pats a day. This amounts to 1.7 billion tonnes a year, enough to smother about 110,000 sq km of pasture, half the area of Victoria.
Dung beetles have become an integral part of the successful management of dairy farms in Australia over the past few decades. A number of species are available from the CSIRO or through a small number of private breeders, most of whom were entomologists with the CSIRO’s dung beetle unit who have taken their specialised knowledge of the insect and opened small businesses in direct competition with their former employer.
1. dung: the droppings or excreta of animals
2. cow pats: droppings of cows
Do the following statements reflect the claims of the writer in Reading Passage 1? In boxes 1-5 on your answer sheet, write:
YES if the statement reflects the claims of the writer
NO if the statement contradicts the claims of the writer
NOT GIVEN if it is impossible to say what the writer thinks about this
1. Bush flies are easier to control than buffalo flies.
2. Four thousand species of dung beetle were initially brought to Australia by the CSIRO.
3. Dung beetles were brought to Australia by the CSIRO over a fourteen-year period.
4. At least twenty-six of the introduced species have become established in Australia.
5. The dung beetles cause an immediate improvement to the quality of a cow pasture.
Label the tunnels on the diagram below. Choose your labels from the box below the diagram. Write your answers in boxes 6-8 on your answer sheet. Write your answers in boxes 6-8 on your answer sheet.
Dung Beetle Types
South African ball roller
Complete the table below.Choose NO MORE THAN THREE WORDS OR A NUMBER from Reading Passage 1 for each answer. Write your answers in boxes 9—13 on your answer sheet.
7. Bài 7
Reading Passage 2 has six sections A-F. Choose the most suitable headings for sections A-D and F from the list of headings below. Write the appropriate numbers i-ix in boxes 14-18 on your answer sheet.
List of Headings
i. The probable effects of the new international trade agreement
ii. The environmental impact of modern farming
iii. Farming and soil erosion
iv. The effects of government policy in rich countries
v. Governments and management of the environment
vi. The effects of government policy in poor countries
vii. Farming and food output
viii. The effects of government policy on food output
ix. The new prospects for world trade
14. Section A
15. Section B
16. Section C
17. Section D
Example: Paragraph E vi
18. Section F
The role of governments in environmental management is difficult but inescapable. Sometimes, the state tries to manage the resources it owns, and does so badly. Often, however, governments act in an even more harmful way. They actually subsidise the exploitation and consumption of natural resources. A whole range of policies, from farm price support to protection for coal-mining, do environmental damage and (often) make no economic sense. Scrapping them offers a two-fold bonus: a cleaner environment and a more efficient economy. Growth and environmentalism can actually go hand in hand if politicians have the courage to confront the vested interest that subsidies create.
No activity affects more of the earth’s surface than farming. It shapes a third of the planet’s land area, not counting Antarctica, and the proportion Is rising. World food output per head has risen by 4 per cent between the 1970s and 1980s mainly as a result of increases in yields from land already in cultivation, but also because more land has been brought under the plough. Higher yields have been achieved by increased irrigation, better crop breeding, and a doubling in the use of pesticides and chemical fertilisers in the 1970s and 1980s.
All these activities may have damaging environmental impacts. For example, land clearing for agriculture is the largest single cause of deforestation; chemical fertilisers and pesticides may contaminate water supplies; more intensive farming and the abandonment of fallow periods tend to exacerbate soil erosion; and the spread of mono-Culture and use of high-yielding varieties of crops have been accompanied by the disappearance of old varieties of food plants which might have provided some insurance against pests or diseases in future. Soil erosion threatens the productivity of land In both rich and poor countries. The United States, where the most careful measurements have been done, discovered in 1982 that about one-fifth of its farmland as losing topsoil at a rate likely to diminish the soil’s productivity. The country subsequently embarked upon a program to convert 11 per cent of its cropped land to meadow or forest. Topsoil in India and China is vanishing much faster than in America.
Government policies have frequently compounded the environmental damage that farming can cause. In the rich countries, subsidies for growing crops and price supports for farm output drive up the price of land.The annual value of these subsidies is immense: about $250 billion, or more than all World Bank lending in the 1980s.To increase the output of crops per acre, a farmer’s easiest option is to use more of the most readily available inputs: fertilisers and pesticides. Fertiliser use doubled in Denmark in the period 1960-1985 and increased in The Netherlands by 150 per cent. The quantity of pesticides applied has risen too; by 69 per cent In 1975-1984 in Denmark, for example, with a rise of 115 per cent in the frequency of application in the three years from 1981.
In the late 1980s and early 1990s some efforts were made to reduce farm subsidies. The most dramatic example was that of New Zealand, which scrapped most farm support in 1984. A study of the environmental effects, conducted in 1993, found that the end of fertiliser subsidies had been followed by a fall in fertiliser use (a fall compounded by the decline in world commodity prices, which cut farm incomes). The removal of subsidies also stopped land-clearing and over-stocking, which in the past had been the principal causes of erosion. Farms began to diversify. The one kind of subsidy whose removal appeared to have been bad for the environment was the subsidy to manage soil erosion.
In less enlightened countries, and in the European Union, the trend has been to reduce rather than eliminate subsidies and to introduce new payments to encourage farmers to treat their land In environmentally friendlier ways, or to leave it follow. It may sound strange but such payments need to be higher than the existing incentives for farmers to grow food crops. Farmers, however, dislike being paid to do nothing. In several countries, they have become interested in the possibility of using fuel produced from crop residues either as a replacement for petrol (as ethanol) or as fuel for power stations (as biomass). Such fuels produce far less carbon dioxide than coal or oil, and absorb carbon dioxide as they grow. They are therefore less likely to contribute to the greenhouse effect. But they die rarely competitive with fossil fuels unless subsidised - and growing them does no less environmental harm than other crops.
In poor countries, governments aggravate other sorts of damage. Subsidies for pesticides and artificial fertilisers encourage farmers to use greater quantities than are needed to get the highest economic crop yield. A study by the International Rice Research Institute Of pesticide use by farmers in South East Asia found that, with pest-resistant varieties of rice, even moderate applications of pesticide frequently cost farmers more than they saved. Such waste puts farmers on a chemical treadmill: bugs and weeds become resistant to poisons, so next year’s poisons must be more lethal. One cost is to human health. Every year some 10,000 people die from pesticide poisoning, almost all of them in the developing countries, and another 400,000 become seriously ill. As for artificial fertilisers, their use worldwide increased by 40 per cent per unit of farmed land between the mid-1970s and late 1980s, mostly in the developing countries. Overuse of fertilisers may cause farmers to stop rotating crops or leaving their land fallow. That, in turn, may make soil erosion worse.
A result of the Uruguay Round of world trade negotiations Is likely to be a reduction of 36 percent In the average levels of farm subsidies paid by the rich countries in 1986-1990. Some of the world’s food production will move from Western Europe to regions where subsidies are lower or non-existent, such as the former communist countries and parts of the developing world. Some environmentalists worry about this outcome. It will be undoubtedly mean more pressure to convert natural habitat into farmland. But it will also have many desirable environmental effects. The intensity of farming in the rich world should decline, and the use of chemical inputs will diminish. Crops are more likely to be grown in the environments to which they are naturally suited. And more farmers in poor countries will have the money and the incentive to manage their land in ways that are sustainable in the long run. That is important. To feed an increasingly hungry world, farmers need every incentive to use their soil and water effectively and efficiently.
Complete the table below using the information in sections B and C of Reading Passage 2. Choose your answers A-G from the box below the table and write them in boxes 19-22 on your answer sheet.
A. Abandonment of fallow period
B. Disappearance of old plant varieties
C. Increased use of chemical inputs
D. Increased irrigation
E. Insurance against pests and diseases
F. Soil erosion
G. Clearing land for cultivation
8. Bài 8
Reading Passage 2 has six sections A-F. Choose the most suitable headings for sections A, B and D from the list of headings below. Write the appropriate numbers i-vii in boxes 13-15 on your answer sheet.
List of Headings
i. Amazonia as unable to sustain complex societies
ii. The role of recent technology in ecological research in Amazonia
iii. The hostility of the indigenous population to North American influences
iv. Recent evidence
v. Early research among the Indian Amazons
vi. The influence of prehistoric inhabitants on Amazonian natural history
vii. The great difficulty of changing local attitudes and practices
13. Section A
14. Section B
Example: Paragraph C. Answer: iv
15. Section D
Secrets of The Forests
A. In 1942 Allan R Holmberg, a doctoral student in anthropology from Yale University, USA, ventured deep into the jungle of Bolivian Amazonia and searched out an isolated band of Siriono Indians. The Siriono, Holmberg later wrote, led a "strikingly backward" existence. Their villages were little more than clusters of thatched huts. Life itself was a perpetual and punishing search for food: some families grew manioc and other starchy crops in small garden plots cleared from the forest, while other members of the tribe scoured the country for small game and promising fish holes. When local resources became depleted, the tribe moved on. As for technology, Holmberg noted, the Siriono "may be classified among the most handicapped peoples of the world". Other than bows, arrows and crude digging sticks, the only tools the Siriono seemed to possess were "two machetes worn to the size of pocket-knives".
B. Although the lives of the Siriono have changed in the intervening decades, the image of them as Stone Age relics has endured. Indeed, in many respects, the Siriono epitomize the popular conception of life in Amazonia. To casual observers, as well as to influential natural scientists and regional planners, the luxuriant forests of Amazonia seem ageless, unconquerable, a habitat totally hostile to human civilization. The apparent simplicity of Indian ways of life has been judged an evolutionary adaptation to forest ecology, living proof that Amazonia could not - and cannot - sustain a more complex society. Archaeological traces of far more elaborate cultures have been dismissed as the ruins of invaders from outside the region, abandoned to decay in the uncompromising tropical environment.
C. The popular conception of Amazonia and its native residents would be enormously consequential if it were true. But the human history of Amazonia in the past 11,000 years betrays that view as myth. Evidence gathered in recent years from anthropology and archaeology indicates that the region has supported a series of indigenous cultures for eleven thousand years; an extensive network of complex societies - some with populations perhaps as large as 100,000 - thrived there for more than 1,000 years before the arrival of Europeans. (Indeed, some contemporary tribes, including the Siriono, still live among the earthworks of earlier cultures.) Far from being evolutionarily retarded, prehistoric Amazonian people developed technologies and cultures that were advanced for their time. If the lives of Indians today seem "primitive", the appearance is not the result of some environmental adaptation or ecological barrier; rather it is a comparatively recent adaptation to centuries of economic and political pressure. Investigators who argue otherwise have unwittingly projected the present onto the past.
D. The evidence for a revised view of Amazonia will take many people by surprise. Ecologists have assumed that tropical ecosystems were shaped entirely by natural forces and they have focused their research on habitats they believe have escaped human influence. But as the University of Florida ecologist, Peter Feinsinger, has noted, an approach that leaves people out of the equation is no longer tenable. The archaeological evidence shows that the natural history of Amazonia is to a surprising extent tied to the activities of its prehistoric inhabitants.
E. The realization comes none too soon. In June 1992 political and environmental leaders from across the world met in Rio de Janeiro to discuss how developing countries can advance their economies without destroying their natural resources. The challenge is especially difficult in Amazonia. Because the tropical forest has been depicted as ecologically unfit for large-scale human occupation, some environmentalists have opposed development of any kind. Ironically, one major casualty of that extreme position has been the environment itself. While policy makers struggle to define and implement appropriate legislation, development of the most destructive kind has continued apace over vast areas.
F. The other major casualty of the "naturalism" of environmental scientists has been the indigenous Amazonians, whose habits of hunting, fishing, and slash-and-burn cultivation often have been represented as harmful to the habitat. In the clash between environmentalists and developers, the Indians, whose presence is, in fact, crucial to the survival of the forest, have suffered the most. The new understanding of the pre-history of Amazonia, however, points toward a middle ground. Archaeology makes clear that with judicious management selected parts of the region could support more people than anyone thought before. The long-buried past, it seems, offers hope for the future.
Do the following statements agree with the views of the writer in Reading Passage 2? In boxes 16—21 on your answer sheet, write :
YES if the statement agrees with the views of the writer
NO if the statement contradicts the views of the writer
NOT GIVEN if it is impossible to say what the writer thinks about this
Example: The prehistoric inhabitants of Amazonia were relatively backward in technological terms. Answer: NO
16. The reason for the simplicity of the Indian way of life is that Amazonia has always been unable to support a more complex society.
17. There is a crucial popular misconception about the human history of Amazonia.
18. There are lessons to be learned from similar ecosystems in other parts of the world.
19. Most ecologists were aware that the areas of Amazonia they were working in had been shaped by human settlement.
20. The indigenous Amazonian Indians are necessary to the well-being of the forest.
21. It would be possible for certain parts of Amazonia to support a higher population.
Choose the appropriate letters A-D and write them in boxes 22-25 on your answer sheet.
22. In 1942 the US anthropology student concluded that the Siriono
A. were unusually aggressive and cruel.
B. had had their way of life destroyed by invaders.
C. were an extremely primitive society.
D. had only recently made permanent settlements.
23. The author believes recent discoveries of the remains of complex societies in Amazonia
A. are evidence of early indigenous communities.
B. are the remains of settlements by invaders.
C. are the ruins of communities established since the European invasions.
D. show the region has only relatively recently been covered by forest.
24. The assumption that the tropical ecosystem of Amazonia has been created solely by natural forces
A. has often been questioned by ecologists in the past.
B. has been shown to be incorrect by recent research.
C. was made by Peter Feinsinger and other ecologists.
D. has led to some fruitful discoveries.
25. The application of our new insights into the Amazonian past would
A. warn us against allowing any development at all.
B. cause further suffering to the Indian communities.
C. change present policies on development in the region.
D. reduce the amount of hunting, fishing, and ‘slash-and-burn’.
9. Bài 9
A. Air pollution is increasingly becoming the focus of government and citizen concern around the globe. From Mexico City and New York to Singapore and Tokyo, new solutions to this old problem are being proposed, Mailed and implemented with ever increasing speed. It is feared that unless pollution reduction measures are able to keep pace with the continued pressures of urban growth, air quality in many of the world’s major cities will deteriorate beyond reason.
B. Action is being taken along several fronts: through new legislation, improved enforcement and innovative technology. In Los Angeles, state regulations are forcing manufacturers to try to sell ever cleaner cars: their first of the cleanest, titled "Zero Emission Vehicles’, have to be available soon, since they are intended to make up 2 percent of sales in 1997. Local authorities in London are campaigning to be allowed to enforce anti-pollution laws themselves; at present only the police have the power to do so, but they tend to be busy elsewhere. In Singapore, renting out road space to users is the way of the future.
C. When Britain’s Royal Automobile Club monitored the exhausts of 60,000 vehicles, it found that 12 percent of them produced more than half the total pollution. Older cars were the worst offenders; though a sizeable number of quite new cars were also identified as gross polluters, they were simply badly tuned. California has developed a scheme to get these gross polluters off the streets: they offer a flat $700 for any old, run-down vehicle driven in by its owner. The aim is to remove the heaviest-polluting, most decrepit vehicles from the roads.
D. As part of a European Union environmental programme, a London council is resting an infra-red spectrometer from the University of Denver in Colorado. It gauges the pollution from a passing vehicle - more useful than the annual stationary rest that is the British standard today - by bouncing a beam through the exhaust and measuring what gets blocked. The council’s next step may be to link the system to a computerised video camera able to read number plates automatically.
E. The effort to clean up cars may do little to cut pollution if nothing is done about the tendency to drive them more. Los Angeles has some of the world’s cleanest cars - far better than those of Europe - but the total number of miles those cars drive continues to grow. One solution is car-pooling, an arrangement in which a number of people who share the same destination share the use of one car. However, the average number of people in a car on the freeway in Los Angeles, which is 1.0, has been falling steadily. Increasing it would be an effective way of reducing emissions as well as easing congestion. The trouble is, Los Angelinos seem to like being alone in their cars.
F. Singapore has for a while had a scheme that forces drivers to buy a badge if they wish to visit a certain part of the city. Electronic innovations make possible increasing sophistication: rates can vary according to road conditions, time of day and so on. Singapore is advancing in this direction, with a city-wide network of transmitters to collect information and charge drivers as they pass certain points. Such road-pricing, however, can be controversial. When the local government in Cambridge, England, considered introducing Singaporean techniques, it faced vocal and ultimately successful opposition.
The scope of the problem facing the world’s cities is immense. In 1992, the United Nations Environmental Programme and the World Health Organisation (WHO) concluded that all of a sample of twenty megacities - places likely to have more than ten million inhabitants in the year 2000 - already exceeded the level the WHO deems healthy in at least one major pollutant. Two-thirds of them exceeded the guidelines for two, seven for three or more.
Of the six pollutants monitored by the WHO - carbon dioxide, nitrogen dioxide, ozone, sulphur dioxide, lead and particulate matter - it is this last category that is attracting the most attention from health researchers. PM10, a sub-category of particulate matter measuring ten-millionths of a meter across, has been implicated in thousands of deaths a year in Britain alone. Research being conducted in two counties of Southern California is reaching similarly disturbing conclusions concerning this little-understood pollutant.
A worldwide rise in allergies, particularly asthma, over the past four decades is now said to be linked with increased air pollution. The lungs and brains of children who grow up in polluted air offer further evidence of its destructive power the old and ill; however, are the most vulnerable to the acute effects of heavily polluted stagnant air. It can actually hasten death, so it did in December 1991 when a cloud of exhaust fumes lingered over the city of London for over a week.
The United Nations has estimated that in the year 2000 there will be twenty-four mega-cities and a further eighty-five cities of more than three million people. The pressure on public officials, corporations and urban citizens to reverse established trends in air pollution is likely to grow in proportion with the growth of cities themselves. Progress is being made. The question, though, remains the same: ‘Will change happen quickly enough?’
Look at the following solutions (Questions 1-5) and locations. Match each solution with one location. Write the appropriate locations in boxes 1-5 on your answer sheet.
NB You may use any location more than once.
1. Manufacturers must sell cleaner cars.
2. Authorities want to have the power to enforce anti-pollution laws.
3. Drivers will be charged according to the roads they use.
4. Moving vehicles will be monitored for their exhaust emissions.
5. Commuters are encouraged to share their vehicles with others.
Do the following statements reflect the claims of the writer in Reading Passage 1? In boxes 6-10 on your answer sheet write:
YES if the statement reflects the claims of the writer
NO if the statement contradicts the claims of the writer
NOT GIVEN if it is impossible to say what the writer thinks about this
6. According to British research, a mere twelve percent of vehicles tested produced over fifty percent of total pollution produced by the sample group.
7. It is currently possible to measure the pollution coming from individual vehicles whilst they are moving.
8. Residents of Los Angeles are now tending to reduce the yearly distances they travel by car.
9. Car-pooling has steadily become more popular in Los Angeles in recent years.
10. Charging drivers for entering certain parts of the city has been successfully done in Cambridge, England.
Choose the appropriate letters A—D and write them in boxes 11-13 on your answer sheet.
11. How many pollutants currently exceed WHO guidelines in all mega cities studied?
12. Which pollutant is currently the subject of urgent research?
A. nitrogen dioxide
D. particulate matter
13. Which of the following groups of people are the most severely affected by intense air pollution?
C. the old and ill
D. asthma sufferers
10. Bài 10
From the list below choose the most suitable title for the whole of the Reading Passage. Write the appropriate letter A-D in box 27 on your answer sheet.
A. Pollution control in coal mining
B. The greenhouse effect
C. The coal industry and the environment
D. Sustainable population growth
The Reading Passage has four sections A-D. Choose the most suitable heading for each section from the list of headings below. Write the appropriate numbers i-viii in boxes 28-31 on your answer sheet.
List of Headings
i. Global warming
ii. The dangers of the coal industry
iii. Superclean coal
iv. Environment protection measures
v. Coal as an energy source
vi. Coal and the enhanced greenhouse effect
vii. Research and development
viii. Mining site drainage
28. Section A
29. Section B
30. Section C
31. Section D
The Coal Industry
A. Coal is expected to continue to account for almost 27 per cent of the world’s energy needs. However, with growing international awareness of pressures on the environment and the need to achieve sustainable development of energy resources, the way in which the resource is extracted, transported and used is critical.
A wide range of pollution control devices and practices is in place at most modern mines and significant resources are spent on rehabilitating mined land. In addition, major research and development programmes are being devoted to lifting efficiencies and reducing emissions of greenhouse gases during coal consumption. Such measures are helping coal to maintain its status as a major supplier of the world’s energy needs.
B. The coal industry has been targeted by its critics as a significant contributor to the greenhouse effect. However, the greenhouse effect is a natural phenomenon involving the increase in global surface temperature due to the presence of greenhouse gases - water vapour, carbon dioxide, tropospheric ozone, methane and nitrous oxide - in the atmosphere. Without the greenhouse effect, the earth’s average surface temperature would be 33-35 degrees C lower, or -15 degrees C. Life on earth, as we know it today, would not be possible.
There is concern that this natural phenomenon is being altered by a greater build-up of gases from human activity, perhaps giving rise to additional warming and changes in the earth’s climate. This additional build-up and its forecast outcome has been called the enhanced greenhouse effect. Considerable uncertainty exists, however, about the enhanced greenhouse effect, particularly in relation to the extent and timing of any future increases in global temperature.
Greenhouse gases arise from a wide range of sources and their increasing concentration is largely related to the compound effects of increased population, improved living standards and changes in lifestyle. From a current base of 5 billion, the United Nations predicts that the global population may stabilise in the twenty-first century between 8 and 14 billion, with more than 90 per cent of the projected increase taking place in the world’s developing nations. The associated activities to support that growth, particularly to produce the required energy and food, will cause further increases in greenhouse gas emissions. The challenge, therefore, is to attain a sustainable balance between population, economic growth and the environment.
The major greenhouse gas emissions from human activities are carbon dioxide (CO2), methane and nitrous oxide. Chlorofluorocarbons (CFCs) are the only major contributor to the greenhouse effect that does not occur naturally, coming from such sources as refrigeration, plastics and manufacture. Coal’s total contribution to greenhouse gas emissions is thought to be about 18 per cent, with about half of this coming from electricity generation.
C. The world-wide coal industry allocates extensive resources to researching and developing new technologies and ways of capturing greenhouse gases. Efficiencies are likely to be improved dramatically, and hence CO2 emissions reduced, through combustion and gasification techniques which are now at pilot and demonstration stages.
Clean coal is another avenue for improving fuel conversion efficiency. Investigations are under way into super clean coal (3-5 per cent ash) and ultraclean coal (less than 1 per cent ash). Superclean coal has the potential to enhance the combustion efficiency of conventional pulverised fuel power plants. Ultraclean coal will enable coal to be used in advanced power systems such as coal-fired gas turbines which, when operated in combined cycle, have the potential to achieve much greater efficiencies.
D. Defendants of mining point out that, environmentally, coal mining has two important factors in its favour. It makes only temporary use of the land and produces no toxic chemical wastes. By carefully pre-planning projects, implementing pollution control measures, monitoring the effects of mining and rehabilitating mined areas, the coal industry minimises the impact on the neighbouring community, the immediate environment and long-term land capability.
Dust levels are controlled by spraying roads and stockpiles, and water pollution is controlled by carefully separating clean water runoff from runoff which contains sediments or salt from mine workings. The latter is treated and re-used for dust suppression. Noise is controlled by modifying equipment and by using insulation and sound enclosures around machinery.
Since mining activities represent only a temporary use of the land, extensive rehabilitation measures are adopted to ensure that land capability after mining meets agreed and appropriate standards which, in some cases, are superior to the land’s pre-mining condition. Where the mining is underground, the surface area can be simultaneously used for forests, cattle grazing and crop raising, or even reservoirs and urban development, with little or no disruption to the existing land use. In all cases, mining is subject to stringent controls and approvals processes.
In open-cut operations, however, the land is used exclusively for mining but land rehabilitation measures generally progress with the mine’s development. As core samples are extracted to assess the quality and quantity of coal at a site, they are also analysed to assess the ability of the soil or subsoil material to support vegetation. Topsoils are stripped and stockpiled prior to mining for subsequent dispersal over rehabilitated areas. As mining ceases in one section of the open-cut, the disturbed area is reshaped. Drainage within and off the site is carefully designed to make the new land surface as stable as the local environment allows: often dams are built to protect the area from soil erosion and to serve as permanent sources of water. Based on the soil requirements, the land is suitably fertilised and revegetated.
Choose the appropriate letters A-D and write them in boxes 32-36 on your answer sheet.
32. The global increase in greenhouse gases has been attributed to
A. industrial pollution in developing countries.
B. coal mining and electricity generation.
C. reduced rainfall in many parts of the world.
D. trends in population and lifestyle.
33. The proportion of all greenhouse gases created by coal is approximately
A. 14 per cent.
B. 18 per cent.
C. 27 per cent.
D. 90 per cent.
34. Current research aims to increase the energy-producing efficiency of coal by
A. burning it at a lower temperature.
B. developing new gasification techniques.
C. extracting CO2 from it.
D. recycling greenhouse gases.
35. Compared with ordinary coal, new, ‘clean’ coals may generate power
A. more cleanly and more efficiently.
B. more cleanly but less efficiently.
C. more cleanly but at higher cost.
D. more cleanly but much more slowly.
36. To control dust at mine sites, mining companies often use
A. chemicals which may be toxic.
B. topsoil taken from the site before mining.
C. fresh water from nearby dams.
D. runoff water containing sediments.
Questions 37- 40
Do the following statements reflect the opinions of the writer in the Reading Passage? In boxes 37-40 on your answer sheet write:
YES if the statement reflects the opinion of the writer
NO if the statement contradicts the writer
NOT GIVEN if it is impossible to say what the writer thinks about this
37. The coal industry should be abandoned in favour of alternative energy sources because of the environmental damage it causes.
38. The greatest threats to the environment are the gases produced by industries which support the high standard of living of a growing world population.
39. World population in the twenty-first century will probably exceed 8 billion.
40. CFC emissions have been substantially reduced in recent years.
11. Bài 11
Adults and children are frequently confronted with statements about the alarming rate of loss of tropical rainforests. For example, one graphic illustration to which children might readily relate is the estimate that rainforests are being destroyed at a rate equivalent to one thousand football fields every forty minutes – about the duration of a normal classroom period. In the face of the frequent and often vivid media coverage, it is likely that children will have formed ideas about rainforests – what and where they are, why they are important, what endangers them – independent of any formal tuition. It is also possible that some of these ideas will be mistaken.
Many studies have shown that children harbour misconceptions about ‘pure’, curriculum science. These misconceptions do not remain isolated but become incorporated into a multifaceted, but organised, conceptual framework, making it and the component ideas, some of which are erroneous, more robust but also accessible to modification. These ideas may be developed by children absorbing ideas through the popular media. Sometimes this information may be erroneous. It seems schools may not be providing an opportunity for children to re-express their ideas and so have them tested and refined by teachers and their peers.
Despite the extensive coverage in the popular media of the destruction of rainforests, little formal information is available about children’s ideas in this area. The aim of the present study is to start to provide such information, to help teachers design their educational strategies to build upon correct ideas and to displace misconceptions and to plan programmes in environmental studies in their schools.
The study surveys children’s scientific knowledge and attitudes to rainforests. Secondary school children were asked to complete a questionnaire containing five open-form questions. The most frequent responses to the first question were descriptions which are self-evident from the term ‘rainforest’. Some children described them as damp, wet or hot. The second question concerned the geographical location of rainforests. The commonest responses were continents or countries: Africa (given by 43% of children), South America (30%), Brazil (25%). Some children also gave more general locations, such as being near the Equator.
Responses to question three concerned the importance of rainforests. The dominant idea, raised by 64% of the pupils, was that rainforests provide animals with habitats. Fewer students responded that rainforests provide plant habitats, and even fewer mentioned the indigenous populations of rainforests. More girls (70%) than boys (60%) raised the idea of the rainforest as animal habitats.
Similarly, but at a lower level, more girls (13%) than boys (5%) said that rainforests provided human habitats. These observations are generally consistent with our previous studies of pupils’ views about the use and conservation of rainforests, in which girls were shown to be more sympathetic to animals and expressed views which seem to place an intrinsic value on non-human animal life.
The fourth question concerned the causes of the destruction of rainforests. Perhaps encouragingly, more than half of the pupils (59%) identified that it is human activities which are destroying rainforests, some personalising the responsibility by the use of terms such as ‘we are’. About 18% of the pupils referred specifically to logging activity.
One misconception, expressed by some 10% of the pupils, was that acid rain is responsible for rainforest destruction; a similar proportion said that pollution is destroying rainforests. Here, children are confusing rainforest destruction with damage to the forests of Western Europe by these factors. While two-fifths of the students provided the information that the rainforests provide oxygen, in some cases this response also embraced the misconception that rainforest destruction would reduce atmospheric oxygen, making the atmosphere incompatible with human life on Earth.
In answer to the final question about the importance of rainforest conservation, the majority of children simply said that we need rainforests to survive. Only a few of the pupils (6%) mentioned that rainforest destruction may contribute to global warming. This is surprising considering the high level of media coverage on this issue. Some children expressed the idea that the conservation of rainforests is not important.
The results of this study suggest that certain ideas predominate in the thinking of children about rainforests. Pupils’ responses indicate some misconceptions in the basic scientific knowledge of rainforests’ ecosystems such as their ideas about rainforests as habitats for animals, plants and humans and the relationship between climatic change and destruction of rainforests.
Pupils did not volunteer ideas that suggested that they appreciated the complexity of causes of rainforest destruction. In other words, they gave no indication of an appreciation of either the range of ways in which rainforests are important or the complex social, economic and political factors which drive the activities which are destroying the rainforests. One encouragement is that the results of similar studies about other environmental issues suggest that older children seem to acquire the ability to appreciate, value and evaluate conflicting views. Environmental education offers an arena in which these skills can be developed, which is essential for these children as future decision-makers.
Do the following statements agree with the information given in Reading Passage 1? In boxes 1–8 on your answer sheet write:
TRUE if the statement agrees with the information
FALSE if the statement contradicts the information
NOT GIVEN if there is no information on this
1. The plight of the rainforests has largely been ignored by the media.
2. Children only accept opinions on rainforests that they encounter in their classrooms.
3. It has been suggested that children hold mistaken views about the ‘pure’ science that they study at school.
4. The fact that children’s ideas about science form part of a larger framework of ideas mean that it is easier to change them.
5. The study involved asking children a number of yes/no questions such as ‘Are there any rainforests in Africa?’
6. Girls are more likely than boys to hold mistaken views about the rainforests’ destruction.
7. The study reported here follows on from a series of studies that have looked at children’s understanding of rainforests.
8. A second study has been planned to investigate primary school children’s ideas about rainforests.
The box below gives a list of responses A–P to the questionnaire discussed in Reading Passage 1.
Answer the following questions by choosing the correct responses A–P. Write your answers in boxes 9–13 on your answer sheet.
09. What was the children’s most frequent response when asked where the rainforests were?
10. What was the most common response to the question about the importance of the rainforests?
11. What did most children give as the reason for the loss of the rainforests?
12. Why did most children think it important for the rainforests to be protected?
13. Which of the responses is cited as unexpectedly uncommon, given the amount of time spent on the issue by the newspapers and television?
A. There is a complicated combination of reasons for the loss of the rainforests.
B. The rainforests are being destroyed by the same things that are destroying the forests of Western Europe.
C. Rainforests are located near the Equator.
D. Brazil is home to the rainforests.
E. Without rainforests some animals would have nowhere to live.
F. Rainforests are important habitats for a lot of plants.
G. People are responsible for the loss of the rainforests.
H. The rainforests are a source of oxygen.
I. Rainforests are of consequence for a number of different reasons.
J. As the rainforests are destroyed, the world gets warmer.
K. Without rainforests there would not be enough oxygen in the air.
L. There are people for whom the rainforests are home.
M. Rainforests are found in Africa.
N. Rainforests are not really important to human life.
O. The destruction of the rainforests is the direct result of logging activity.
P. Humans depend on the rainforests for their continuing existence.
Choose the correct letter A, B, C, D or E. Write your answer in box 14 on your answer sheet.
Which of the following is the most suitable title for Reading Passage 1?
A. The development of a programme in environmental studies within a science curriculum
B. Children’s ideas about the rainforests and the implications for course design
C. The extent to which children have been misled by the media concerning the rainforests
D. How to collect, collate and describe the ideas of secondary school children
E. The importance of the rainforests and the reasons for their destruction
12. Bài 12
What Do Whales Feel?
An examination of the functioning of the senses in cetaceans, the group of mammals comprising whales, dolphins and porpoises.
Some of the senses that we and other terrestrial mammals take for granted are either reduced or absent in cetaceans or fail to function well in water. For example, it appears from their brain structure that toothed species are unable to smell. Baleen species, on the other hand, appear to have some related brain structures but it is not known whether these are functional. It has been speculated that, as the blowholes evolved and migrated to the top of the head, the neural pathways serving sense of smell may have been nearly all sacrificed. Similarly, although at least some cetaceans have taste buds, the nerves serving these have degenerated or are rudimentary.
The sense of touch has sometimes been described as weak too, but this view is probably mistaken. Trainers of captive dolphins and small whales often remark on their animals’ responsiveness to being touched or rubbed, and both captive and free ranging cetacean individuals of all species (particularly adults and calves, or members of the same subgroup) appear to make frequent contact. This contact may help to maintain order within a group, and stroking or touching are part of the courtship ritual in most species. The area around the blowhole is also particularly sensitive and captive animals often object strongly to being touched there.
The sense of vision is developed to different degrees in different species. Baleen species studied at close quarters underwater – specifically a grey whale calf in captivity for a year, and free-ranging right whales and humpback whales studied and filmed off Argentina and Hawaii – have obviously tracked objects with vision underwater, and they can apparently see moderately well both in water and in air. However, the position of the eyes so restricts the field of vision in baleen whales that they probably do not have stereoscopic vision.
On the other hand, the position of the eyes in most dolphins and porpoises suggests that they have stereoscopic vision forward and downward. Eye position in freshwater dolphins, which often swim on their side or upside down while feeding, suggests that what vision they have is stereoscopic forward and upward. By comparison, the bottlenose dolphin has an extremely keen vision in water. Judging from the way it watches and tracks airborne flying fish, it can apparently see fairly well through the air–water interface as well. And although preliminary experimental evidence suggests that their in-air vision is poor, the accuracy with which dolphins leap high to take small fish out of a trainer’s hand provides anecdotal evidence to the contrary.
Such variation can no doubt be explained with reference to the habitats in which individual species have developed. For example, vision is obviously more useful to species inhabiting clear open waters than to those living in turbid rivers and flooded plains. The South American boutu and Chinese beiji, for instance, appear to have very limited vision, and the Indian susus are blind, their eyes reduced to slits that probably allow them to sense only the direction and intensity of light.
Although the senses of taste and smell appear to have deteriorated, and vision in water appears to be uncertain, such weaknesses are more than compensated for by cetaceans’ well-developed acoustic sense. Most species are highly vocal, although they vary in the range of sounds they produce, and many forage for food using echolocation1. Large baleen whales primarily use the lower frequencies and are often limited in their repertoire. Notable exceptions are the nearly song-like choruses of bowhead whales in summer and the complex, haunting utterances of the humpback whales. Toothed species, in general, employ more of the frequency spectrum, and produce a wider variety of sounds than baleen species (though the sperm whale apparently produces a monotonous series of high-energy clicks and little else). Some of the more complicated sounds are clearly communicative, although what role they may play in the social life and ‘culture’ of cetaceans has been more the subject of wild speculation than of solid science.
1. echolocation: the perception of objects by means of sound wave echoes.
Complete the table below. Choose NO MORE THAN THREE WORDS from Reading Passage 2 for each answer. Write your answers in boxes 15–21 on your answer sheet.
Answer the questions below using NO MORE THAN THREE WORDS from the passage for each answer. Write your answers in boxes 22–26 on your answer sheet.
22. Which of the senses is described here as being involved in mating?
23. Which species swims upside down while eating?
24. What can bottlenose dolphins follow from under the water?
25. Which type of habitat is related to good visual ability?
26. Which of the senses is best developed in cetaceans?
13. Bài 13
Reading Passage 2 has four sections A-D. Choose the correct heading for the each section from the list of headings below. Write the correct number i-vi in boxes 14-17 on your answer sheet.
List of Headings
i. Causes of volcanic eruption
ii. Efforts to predict volcanic eruption
iii. Volcanoes and the features of our planet
iv. Different types of volcanic eruption
v. International relief efforts
vi.The unpredictability of volcanic eruption
14. Section A
15. Section B
16. Section C
17. Section D
Volcanoes – earth-shattering news
When Mount Pinatubo suddenly erupted on 9 June 1991, the power of volcanoes past and present again hit the headlines.
A. Volcanoes are the ultimate earth-moving machinery. A violent eruption can blow the top few kilometres off a mountain, scatter fine ash practically all over the globe and hurt rock fragments into the stratosphere to darken the skies a continent away.
Earth shattering news But the classic eruption – cone-shaped mountain, big bang, mushroom cloud and surges of molten lava – is only a tiny part of a global story. Volcanism, the name given to volcanic processes, really has shaped the world. Eruptions have rifted continents, raised mountain chains, constructed islands and shaped the topography of the earth. The entire ocean floor has a basement of volcanic basalt.
Volcanoes have not only made the continents, they are also thought to have made the world’s first stable atmosphere and provided all the water for the oceans, rivers and ice-caps. There are now about 600 active volcanoes. Every year they add two or three cubic kilometres of rock to the continents. Imagine a similar number of volcanoes smoking away for the last 3,500 million years. That is enough rock to explain the continental crust.
What comes out of volcanic craters is mostly gas. More than 90% of this gas is water vapour from the deep earth: enough to explain, over 3,500 million years, the water in the oceans. The rest of the gas is nitrogen, carbon dioxide, sulphur dioxide, methane, ammonia and hydrogen. The quantity of these gases, again multiplied over 3,500 million years, is enough to explain the mass of the world’s atmosphere. We are alive because volcanoes provided the soil, air and water we need.
B. Geologists consider the earth as having a molten core, surrounded by a semi-molten mantle and a brittle, outer skin. It helps to think of a soft-boiled egg with a runny yolk, a firm but squishy white and a hard shell. If the shell is even slightly cracked during boiling, the white material bubbles out and sets like a tiny mountain chain over the crack – like an archipelago of volcanic islands such as the Hawaiian Islands. But the earth is so much bigger and the mantle below is so much halter.
Even though the mantle rocks are kept solid by overlying pressure, they can still slowly ‘flow’ like thick treacle. The flow, thought to be in the form of convection currents, is powerful enough to fracture the ‘eggshell’ of the crust into plates, and keep them bumping and grinding against each other, or even overlapping, at the rate of a few centimetres a year. These fracture zones, where the collisions occur, are where earthquakes happen. And, very often, volcanoes.
C. These zones are lines of weakness, or hot spots. Every eruption is different, but put at its simplest, where there are weaknesses, rocks deep in the mantle, heated to 1,350oC, will start to expand and rise. As they do so, the pressure drops, and they expand and become liquid and rise more swiftly.
Sometimes it is slow: vast bubbles of magma – molten rock from the mantle – inch towards the surface, cooling slowly, to show through as granite extrusions (as on Skye, or the Great Whin Sill, the lava dyke squeezed out like toothpaste that carries part of Hadrian’s Wall in northern England). Sometimes – as in Northern Ireland, Wales and the Karoo in South Africa – the magma rose faster, and then flowed out horizontally on to the surface in vast thick sheets. In the Deccan plateau in western India, there are more than two million cubic kilometres of lava, some of it 2,400 metres thick, formed over 500,000 years of slurping eruption.
Sometimes the magma moves very swiftly indeed. It does not have time to cool as it surges upwards. The gases trapped inside the boiling rock expand suddenly, the lava glows with heat, it begins to froth, and it explodes with tremendous force. Then the slightly cooler lava following it begins to flow over the lip of the crater. It happens on Mars, it happened on the moon, it even happens on some of the moons of Jupiter and Uranus. By studying the evidence, vulcanologists can read the force of the great blasts of the past. Is the pumice light and full of holes? The explosion was tremendous. Are the rocks heavy, with huge crystalline basalt shapes, like the Giant’s Causeway in Northern Ireland? It was a slow, gentle eruption.
The biggest eruptions are deep on the mid-ocean floor, where new lava is forcing the continents apart and widening the Atlantic by perhaps five centimetres a year. Look at maps of volcanoes, earthquakes and island chains like the Philippines and Japan, and you can see the rough outlines of what are called tectonic plates – the plates which make up the earth’s crust and mantle. The most dramatic of these is the Pacific ‘ring of fire’ where there have the most violent explosions – Mount Pinatubo near Manila, Mount St Helen’s in the Rockies and El Chichón in Mexico about a decade ago, not to mention world-shaking blasts like Krakatoa in the Sunda Straits in 1883.
D. But volcanoes are not very predictable. That is because geological time is not like human time. During quiet periods, volcanoes cap themselves with their own lava by forming a powerful cone from the molten rocks slopping over the rim of the crater; later the lava cools slowly into a huge, hard, stable plug which blocks any further eruption until the pressure below becomes irresistible. In the case of Mount Pinatubo, this took 600 years.
Then, sometimes, with only a small warning, the mountain blows its top. It did this at Mont Pelée in Martinique at 7.49 a.m. on 8 May, 1902. Of a town of 28,000, only two people survived. In 1815, a sudden blast removed the top 1,280 metres of Mount Tambora in Indonesia. The eruption was so fierce that dust thrown into the stratosphere darkened the skies, canceling the following summer in Europe and North America. Thousands starved as the harvest failed, after snow in June and frosts in August. Volcanoes are potentially world news, especially the quiet ones.
Answer the questions below using NO MORE THAN THREE WORDS AND/ OR A NUMBER from the passage for each answer. Write your answers in boxes 18-21 on your answer sheet.
18. What are the sections of the earth’s crust, often associated with volcanic activity, called?
19. What is the name given to molten rock from the mantle?
20. What is the earthquake zone on the Pacific Ocean called?
21. For how many years did Mount Pinatubo remain inactive?
Complete the summary below. Choose NO MORE THAN TWO WORDS from the passage for each answer. Write your answers in boxes 22-26 on your answer sheets.
Volcanic eruptions have shaped the earth’s land surface. They may also have produced the world’s atmosphere and 22 …...…… Eruptions occur when molten rocks from the earth’s mantle rise and expand. When they become liquid, they move more quickly through cracks in the surface. There are different types of eruption. Sometimes the 23 ……...… moves slowly and forms outcrops of granite on the earth’s surface. When it moves more quickly it may flow out in thick horizontal sheets. Examples of this type of eruption can be found in Northern Ireland, Wales, South Africa and 24 …...…… A third type of eruption occurs when the lava emerges very quickly and 25 …...…… violently. This happens because the magma moves so suddenly that 26 …...…… are emitted.