Tổng hợp topic Environment (Biology, Agriculture,...) IELTS READING (PDF)(Phần 4)

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II. Tổng hợp topic Environment (Biology, Agriculture,...) IELTS READING (PDF) (Phần 4)

40. Bài 40

Bring back the big cats

It's time to start returning vanished native animals to Britain, says John Vesty

There is a poem, written around 598 AD, which describes hunting a mystery animal called a llewyn. But what was it? Nothing seemed to fit, until 2006, when an animal bone, dating from around the same period, was found in the Kinsey Cave in northern England. Until this discovery, the lynx - a large spotted cat with tassel led ears - was presumed to have died out in Britain at least 6,000 years ago, before the inhabitants of these islands took up farming. But the 2006 find, together with three others in Yorkshire and Scotland, is compelling evidence that the lynx and the mysterious llewyn were, in fact, one and the same animal. If this is so, it would bring forward the tassel-eared cat's estimated extinction date by roughly 5,000 years.

However, this is not quite the last glimpse of the animal in British culture. A 9th- century stone cross from the Isle of Eigg shows, alongside the deer, boar and aurochs pursued by a mounted hunter, a speckled cat with tasselled ears. Were it not for the animal's backside having worn away with time, we could have been certain, as the lynx's stubby tail is unmistakable. But even without this key feature, it's hard to see what else the creature could have been. The lynx is now becoming the totemic animal of a movement that is transforming British environmentalism: rewilding.

Rewilding means the mass restoration of damaged ecosystems. It involves letting trees return to places that have been denuded, allowing parts of the seabed to recover from trawling and dredging, permitting rivers to flow freely again. Above all, it means bringing back missing species. One of the most striking findings of modern ecology is that ecosystems without large predators behave in completely different ways from those that retain them Some of them drive dynamic processes that resonate through the whole food chain, creating niches for hundreds of species that might otherwise struggle to survive. The killers turn out to be bringers of life.

Such findings present a big challenge to British conservation, which has often selected arbitrary assemblages of plants and animals and sought, at great effort and expense, to prevent them from changing. It has tried to preserve the living world as if it were a jar of pickles, letting nothing in and nothing out, keeping nature in a state of arrested development. But ecosystems are not merely collections of species; they are also the dynamic and ever-shifting relationships between them. And this dynamism often depends on large predators.

At sea the potential is even greater: by protecting large areas from commercial fishing, we could once more see what 18th-century literature describes: vast shoals of fish being chased by fin and sperm whales, within sight of the English shore. This policy would also greatly boost catches in the surrounding seas; the fishing industry's insistence on scouring every inch of seabed, leaving no breeding reserves, could not be more damaging to its own interests.

Rewilding is a rare example of an environmental movement in which campaigners articulate what they are for rather than only what they are against. One of the reasons why the enthusiasm for rewilding is spreading so quickly in Britain is that it helps to create a more inspiring vision than the green movement's usual promise of 'Follow us and the world will be slightly less awful than it would otherwise have been.

The lynx presents no threat to human beings: there is no known instance of one preying on people. It is a specialist predator of roe deer, a species that has exploded in Britain in recent decades, holding back, by intensive browsing, attempts to re-establish forests. It will also winkle out sika deer: an exotic species that is almost impossible for human beings to control, as it hides in impenetrable plantations of young trees. The attempt to reintroduce this predator marries well with the aim of bringing forests back to parts of our bare and barren uplands. The lynx requires deep cover, and as such presents little risk to sheep and other livestock, which are supposed, as a condition of farm subsidies, to be kept out of the woods.

On a recent trip to the Cairngorm Mountains, I heard several conservationists suggest that the lynx could be reintroduced there within 20 years. If trees return to the bare hills elsewhere in Britain, the big cats could soon follow. There is nothing extraordinary about these proposals, seen from the perspective of anywhere else in Europe. The lynx has now been reintroduced to the Jura Mountains, the Alps, the Vosges in eastern France and the Harz mountains in Germany, and has re-established itself in many more places. The European population has tripled since 1970 to roughly 10,000. As with wolves, bears, beavers, boar, bison, moose and many other species, the lynx has been able to spread as farming has, left the hills and people discover that it is more lucrative to protect charismatic wildlife than to hunt it, as tourists will pay for the chance to see it. Large-scale rewilding is happening almost everywhere - except Britain.

Here, attitudes are just beginning to change. Conservationists are starting to accept that the old preservation-jar model is failing, even on its own terms. Already, projects such as Trees for Life in the Highlands provide a hint of what might be coming. An organisation is being set up that will seek to catalyse the rewilding of land and sea across Britain, its aim being to reintroduce that rarest of species to British ecosystems: hope.

Questions 14-18

Write the correct letter, A, B, C or D, in boxes 14-18 on your answer sheet.

14.  What did the 2006 discovery of the animal bone reveal about the lynx?

    A. Its physical appearance was very distinctive.
    B. Its extinction was linked to the spread of farming.
    C. It vanished from Britain several thousand years ago.
    D. It survived in Britain longer than was previously thought.

15.  What point does the writer make about large predators in the third paragraph?

    A. Their presence can increase biodiversity.
    B. They may cause damage to local ecosystems.
    C. Their behaviour can alter according to the environment.
    D. They should be reintroduced only to areas where they were native.

16.  What does the writer suggest about British conservation in the fourth paragraph?

    A. It has failed to achieve its aims.
    B. It is beginning to change direction.
    C. it has taken a misguided approach.
    D. It has focused on the most widespread species.

17.  Protecting large areas of the sea from commercial fishing would result in

    A. practical benefits for the fishing industry.
    B. some short-term losses to the fishing industry.
    C. widespread opposition from the fishing industry.
    D. certain changes to techniques within the fishing industry.

18. According to the author, what distinguishes rewilding from other environmental campaigns?

    A. Its objective is more achievable.
    B. Its supporters are more articulate.
    C. Its positive message is more appealing.
    D. It is based on sounder scientific principles.

Questions 19-22

Complete the summary using the list of words and phrases A-F below. Write the correct letter, A-F, in boxes 19-22 on your answer sheet.

Reintroducing the lynx to Britain

There would be many advantages to reintroducing the lynx to Britain. While there is no evidence that the lynx has ever put 19......................
in danger, it would reduce the numbers of certain 20...................... whose populations have increased enormously in recent decades. It would present only a minimal threat to 21......................, provided these were kept away from lynx habitats. Furthermore, the reintroduction programme would also link efficiently with initiatives to return native 22...................... to certain areas of the country.

A.  trees
B.  endangered species
C.  hillsides
D.  wild animals
E.  humans
F. farm animals

Questions 23-26

Do the following statements agree with the claims of the writer in Reading Passage 2? In boxes 23-26 on your answer sheet, write:

YES    if the statement agrees with 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

23. Britain could become the first European country to reintroduce the lynx.
24. The large growth in the European lynx population since 1970 has exceeded conservationists’ expectations.
25. Changes in agricultural practices have extended the habitat of the lynx in Europe.
26. It has become apparent that species reintroduction has commercial advantages.

41. Bài 41

The coconut palm

For millennia, the coconut has been central to the lives of Polynesian and Asian peoples. In the western world, on the other hand, coconuts have always been exotic and unusual, sometimes rare. The Italian merchant traveller Marco Polo apparently saw coconuts in South Asia in the late 13th century, and among the mid-14th-century travel writings of Sir John Mandeville there is mention of ‘great Notes of Ynde’ (great Nuts of India). Today, images of palm-fringed tropical beaches are clichés in the west to sell holidays, chocolate bars, fizzy drinks and even romance.

Typically, we envisage coconuts as brown cannonballs that, when opened, provide sweet white flesh. But we see only part of the fruit and none of the plant from which they come. The coconut palm has a smooth, slender, grey trunk, up to 30 metres tall. This is an important source of timber for building houses, and is increasingly being used as a replacement for endangered hardwoods in the furniture construction industry. The trunk is surmounted by a rosette of leaves, each of which may be up to six metres long. The leaves have hard veins in their centres which, in many parts of the world, are used as brushes after the green part of the leaf has been stripped away. Immature coconut flowers are tightly clustered together among the leaves at the top of the trunk. The flower stems may be tapped for their sap to produce a drink, and the sap can also be reduced by boiling to produce a type of sugar used for cooking.
Coconut palms produce as many as seventy fruits per year, weighing more than a kilogram each. The wall of the fruit has three layers: a waterproof outer layer, a fibrous middle layer and a hard, inner layer. The thick fibrous middle layer produces coconut fibre, ‘coir’, which has numerous uses and is particularly important in manufacturing ropes. The woody innermost layer, the shell, with its three prominent ‘eyes’, surrounds the seed. An important product obtained from the shell is charcoal, which is widely used in various industries as well as in the home as a cooking fuel. When broken in half, the shells are also used as bowls in many parts of Asia.

Inside the shell are the nutrients (endosperm) needed by the developing seed. Initially, the endosperm is a sweetish liquid, coconut water, which is enjoyed as a drink, but also provides the hormones which encourage other plants to grow more rapidly and produce higher yields. As the fruit matures, the coconut water gradually solidifies to form the brilliant white, fat-rich, edible flesh or meat. Dried coconut flesh, ‘copra’, is made into coconut oil and coconut milk, which are widely used in cooking in different parts of the world, as well as in cosmetics. A derivative of coconut fat, glycerine, acquired strategic importance in a quite different sphere, as Alfred Nobel introduced the world to his nitroglycerine-based invention: dynamite.

Their biology would appear to make coconuts the great maritime voyagers and coastal colonizers of the plant world. The large, energy-rich fruits are able to float in water and tolerate salt, but cannot remain viable indefinitely; studies suggest after about 110 days at sea they are no longer able to germinate. Literally cast onto desert island shores, with little more than sand to grow in and exposed to the full glare of the tropical sun, coconut seeds are able to germinate and root. The air pocket in the seed, created as the endosperm solidifies, protects the embryo. In addition, the fibrous fruit wall that helped it to float during the voyage stores moisture that can be taken up by the roots of the coconut seedling as it starts to grow.
There have been centuries of academic debate over the origins of the coconut. There were no coconut palms in West Africa, the Caribbean or the east coast of the Americans before the voyages of the European explorers Vasco da Gama and Columbus in the late 15th and early 16th centuries. 16th century trade and human migration patterns reveal that Arab traders and European sailors are likely to have moved coconuts from South and Southeast Asia to Africa and then across the Atlantic to the east coast of America. But the origin of coconuts discovered along the west coast of America by 16th century sailors has been the subject of centuries of discussion. Two diametrically opposed origins have been proposed: that they came from Asia, or that they were native to America. Both suggestions have problems. In Asia, there is a large degree of coconut diversity and evidence of millennia of human use – but there are no relatives growing in the wild. In America, there are close coconut relatives, but no evidence that coconuts are indigenous. These problems have led to the intriguing suggestion that coconuts originated on coral islands in the Pacific and were dispersed from there.

Questions 1-8
Complete the table below. Choose ONE WORD ONLY from the passage for each answer. Write your answers in boxes 1-8 on your answer sheet.

The coconut palm

Questions 9-13
Do the following statements agree with the information given in Reading Passage 1? In boxes 9-13 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

9. Coconut seeds need shade in order to germinate.

10. Coconuts were probably transported to Asia from America in the 16th century.

11. Coconuts found on the west coast of America were a different type from those found on the east coast.

12. All the coconuts found in Asia are cultivated varieties.

13. Coconuts are cultivated in different ways in America and the Pacific.

42. Bài 42

SAVING THE SOIL

More than a third of the Earth’s top layer is at risk. Is there hope for our planet’s most precious resource?

A. More than a third of the world’s soil is endangered, according to a recent UN report. If we don’t slow the decline, all farmable soil could be gone in 60 years. Since soil grows 95% of our food, and sustains human life in other more surprising ways, that is a huge problem.

B. Peter Groffman, from the Cary Institute of Ecosystem Studies in New York, points out that soil scientists have been warning about the degradation of the world’s soil for decades. At the same time, our understanding of its importance to humans has grown. A single gram of healthy soil might contain 100 million bacteria, as well as other microorganisms such as viruses and fungi, living amid decomposing plants and various minerals.

That means soils do not just grow our food, but are the source of nearly all our existing antibiotics, and could be our best hope in the fight against antibiotic-resistant bacteria. Soil is also an ally against climate change: as microorganisms within soil digest dead animals and plants, they lock in their carbon content, holding three times the amount of carbon as does the entire atmosphere. Soils also store water, preventing flood damage: in the UK, damage to buildings, roads and bridges from floods caused by soil degradation costs £233 million every year.

C. If the soil loses its ability to perform these functions, the human race could be in big trouble. The danger is not that the soil will disappear completely, but that the microorganisms that give it its special properties will be lost. And once this has happened, it may take the soil thousands of years to recover.

Agriculture is by far the biggest problem. In the wild, when plants grow they remove nutrients from the soil, but then when the plants die and decay these nutrients are returned directly to the soil. Humans tend not to return unused parts of harvested crops directly to the soil to enrich it, meaning that the soil gradually becomes less fertile. In the past we developed strategies to get around the problem, such as regularly varying the types of crops grown, or leaving fields uncultivated for a season.

D. But these practices became inconvenient as populations grew and agriculture had to be run on more commercial lines. A solution came in the early 20th century with the Haber-Bosch process for manufacturing ammonium nitrate. Farmers have been putting this synthetic fertiliser on their fields ever since.

But over the past few decades, it has become clear this wasn’t such a bright idea. Chemical fertilisers can release polluting nitrous oxide into the atmosphere and excess is often washed away with the rain, releasing nitrogen into rivers. More recently, we have found that indiscriminate use of fertilisers hurts the soil itself, turning it acidic and salty, and degrading the soil they are supposed to nourish.

E. One of the people looking for a solution to his problem is Pius Floris, who started out running a tree-care business in the Netherlands, and now advises some of the world’s top soil scientists. He came to realise that the best way to ensure his trees flourished was to take care of the soil, and has developed a cocktail of beneficial bacteria, fungi and humus* to do this. Researchers at the University of Valladolid in Spain recently used this cocktail on soils destroyed by years of fertiliser overuse. When they applied Floris’s mix to the desert-like test plots, a good crop of plants emerged that were not just healthy at the surface, but had roots strong enough to pierce dirt as hard as rock. The few plants that grew in the control plots, fed with traditional fertilisers, were small and weak.

F. However, measures like this are not enough to solve the global soil degradation problem. To assess our options on a global scale we first need an accurate picture of what types of soil are out there, and the problems they face. That’s not easy. For one thing, there is no agreed international system for classifying soil. In an attempt to unify the different approaches, the UN has created the Global Soil Map project. Researchers from nine countries are working together to create a map linked to a database that can be fed measurements from field surveys, drone surveys, satellite imagery, lad analyses and so on to provide real-time data on the state of the soil. Within the next four years, they aim to have mapped soils worldwide to a depth of 100 metres, with the results freely accessible to all.

G. But this is only a first step. We need ways of presenting the problem that bring it home to governments and the wider public, says Pamela Chasek at the International Institute for Sustainable Development, in Winnipeg, Canada. ‘Most scientists don’t speak language that policy-makers can understand, and vice versa.’ Chasek and her colleagues have proposed a goal of ‘zero net land degradation’. Like the idea of carbon neutrality, it is an easily understood target that can help shape expectations and encourage action.

For soils on the brink, that may be too late. Several researchers are agitating for the immediate creation of protected zones for endangered soils. One difficulty here is defining what these areas should conserve: areas where the greatest soil diversity is present? Or areas of unspoilt soils that could act as a future benchmark of quality?
Whatever we do, if we want our soils to survive, we need to take action now.

Questions 14-17
Complete the summary below. Write ONE WORD ONLY from the passage for each answer. Write your answers in boxes 14-17 on your answer sheet.

Why soil degradation could be a disaster for humans

Healthy soil contains a large variety of bacteria and other microorganisms, as well as plant remains and 14 ………….. It provides us with food and also with antibiotics, and its function in storing 15 ………………. has a significant effect on the climate. In addition, it prevents damage to property and infrastructure because it holds 16………………………

If these microorganisms are lost, soil may lose its special properties. The main factor contributing to soil degradation is the 17………………………….. carried out by humans.

Questions 18-21
Complete each sentence with the correct ending, A-F, below. Write the correct letter, A-F, in boxes 18-21 on your answer sheet.

18. Nutrients contained in the unused parts of harvested crops

19. Synthetic fertilisers produced with Haber-Bosch process
20. Addition of a mixture developed by Pius Floris to the soil

21. The idea of zero net soil degradation
A. may improve the number and quality of plants growing there.

B. may contain data from up to nine countries.

C. may not be put back into the soil.

D. may help governments to be more aware of soil-related issues.

E. may cause damage to different aspects of the environment.

F. may be better for use at a global level.

Questions 22-26
Reading Passage 2 has seven paragraphs, A-G.

Which section contains the following information?

Write the correct letter, A-G, in boxes 22-26 on your answer sheet.

NB You may use any letter more than once.
22. a reference to one person’s motivation for a soil-improvement project

23. an explanation of how soil stayed healthy before the development of farming

24. examples of different ways of collecting information on soil degradation

25. a suggestion for a way of keeping some types of soil safe in the near future

26. a reason why it is difficult to provide an overview of soil degradation

43. Bài 43

Why zoos are good

Scientist David Hone makes the case for zoos

A. In my view, it is perfectly possible for many species of animals living in zoos or wildlife parks to have a quality of life as high as, or higher than, in the wild. Animals in good zoos get a varied and high-quality diet with all the supplements required, and any illnesses they might have will be treated. Their movement might be somewhat restricted, but they have a safe environment in which to live, and they are spared bullying and social ostracism by others of their kind. They do not suffer from the threat or stress of predators, or the irritation and pain of parasites or injuries. The average captive animal will have a greater life expectancy compared with its wild counterpart, and will not die of drought, of starvation or in the jaws of a predator. A lot of very nasty things happen to truly ‘wild’ animals that simply don’t happen in good zoos, and to view a life that is ‘free’ as one that is automatically ‘good’ is, I think, an error. Furthermore, zoos serve several key purposes.

B. Firstly, zoos aid conservation. Colossal numbers of species are becoming extinct across the world, and many more are increasingly threatened and therefore risk extinction. Moreover, some of these collapses have been sudden, dramatic and unexpected, or were simply discovered very late in the day. A species protected in captivity can be bred up to provide a reservoir population against a population crash or extinction in the wild. A good number of species only exist in captivity, with many of these living in zoos. Still more only exist in the wild because they have been reintroduced from zoos, or have wild populations that have been boosted by captive bred animals. Without these efforts there would be fewer species alive today. Although reintroduction successes are few and far between, the numbers are increasing, and the very fact that species have been saved or reintroduced as a result of captive breeding proves the value of such initiatives.

C. Zoos also provide education. Many children and adults, especially those in cities, will never see a wild animal beyond a fox or pigeon. While it is true that television documentaries are becoming ever more detailed and impressive, and many natural history specimens are on display in museums, there really is nothing to compare with seeing a living creature in the flesh, hearing it, smelling it, watching what it does and having the time to absorb details. That alone will bring a greater understanding and perspective to many, and hopefully give them a greater appreciation for wildlife, conservation efforts and how they can contribute.

D. In addition to this, there is also the education that can take place in zoos through signs, talks and presentations which directly communicate information to visitors about the animals they are seeing and their place in the world. This was an area where zoos used to be lacking, but they are now increasingly sophisticated in their communication and outreach work. Many zoos also work directly to educate conservation workers in other countries, or send their animal keepers abroad to contribute their knowledge and skills to those working in zoos and reserves, thereby helping to improve conditions and reintroductions all over the world.

E. Zoos also play a key role in research. If we are to save wild species and restore and repair ecosystems we need to know about how key species live, act and react. Being able to undertake research on animals in zoos where there is less risk and fewer variables means real changes can be effected on wild populations. Finding out about, for example, the oestrus cycle of an animal of its breeding rate helps us manage wild populations. Procedures such as capturing and moving at-risk or dangerous individuals are bolstered by knowledge gained in zoos about doses for anaesthetics, and by experience in handling and transporting animals. This can make a real difference to conservation efforts and to the reduction of human-animal conflicts, and can provide a knowledge base for helping with the increasing threats of habitat destruction and other problems.

F. In conclusion, considering the many ongoing global threats to the environment, it is hard for me to see zoos as anything other than essential to the long-term survival of numerous species. They are vital not just in terms of protecting animals, but as a means of learning about them to aid those still in the wild, as well as educating and informing the general population about these animals and their world so that they can assist or at least accept the need to be more environmentally conscious. Without them, the world would be, and would increasingly become, a much poorer place.

Questions 14-17
Reading Passage 2 has six paragraphs, A-F.

Which paragraph contains the following information?

Write the correct letter, A-F, in boxes 14-17 on your answer sheet.
14. a reference to how quickly animal species can die out

15. reasons why it is preferable to study animals in captivity rather than in the wild

16. mention of two ways of learning about animals other than visiting them in zoos

17. reasons why animals in zoos may by healthier than those in the wild

Questions 18-22
Do the following statements agree with the information given in Reading Passage 2? In boxes 18-22 on you 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

18. An animal is likely to live longer in a zoo than in the wild

19. There are some species in zoos which can no longer be found in the wild.

20. Improvements in the quality of TV wildlife documentaries have resulted in increased numbers of zoo visitors.
21. Zoos have always excelled at transmitting information about animals to the public.
22. Studying animals in zoos is less stressful for the animals than studying them in the wild.

Questions 23 and 24
Choose TWO letters, A-E. Write the correct letters in boxes 23 and 24 on your answer sheet.

Which TWO of the following are stated about zoo staff in the text?

A. Some take part in television documentaries about animals

B. Some travel to overseas locations to join teams in zoos.

C. Some get experience with species in the wild before taking up zoo jobs.

D. Some teach people who are involved with conservation projects.

E. Some specialise in caring for species which are under threat.

Questions 25 and 26

Choose TWO letters, A-E. Write the correct letters in boxes 25 and 26 on your answer sheet.

Which TWO of these beliefs about zoos does the writer mention in the text?

A. They can help children overcome their fears of wild animals.

B. They can increase public awareness of environmental issues.

C. They can provide employment for a range of professional people.

D. They can generate income to support wildlife conservation projects.

E. They can raise animals which can later be released into the wild.

44. Bài 44

Chelsea Rochman, an ecologist at the University of California, Davis, has been trying to answer a dismal question: Is everything terrible, or are things just very, very bad?

Rochman is a member of the National Center for Ecological Analysis and Synthesis’s marine-debris working group, a collection of scientists who study, among other things, the growing problem of marine debris, also known as ocean trash. Plenty of studies have sounded alarm bells about the state of marine debris; in a recent paper published in the journal Ecology, Rochman and her colleagues set out to determine how many of those perceived risks are real.

Often, Rochman says, scientists will end a paper by speculating about the broader impacts of what they’ve found. For example, a study could show that certain seabirds eat plastic bags, and go on to warn that whole bird populations are at risk of dying out. ‘But the truth was that nobody had yet tested those perceived threats,’ Rochman says. ‘There wasn’t a lot of information.’

Rochman and her colleagues examined more than a hundred papers on the impacts of marine debris that were published through 2013. Within each paper, they asked what threats scientists had studied – 366 perceived threats in all – and what they’d actually found.

In 83 percent of cases, the perceived dangers of ocean trash were proven true. In the remaining cases, the working group found the studies had weaknesses in design and content which affected the validity of their conclusions – they lacked a control group, for example, or used faulty statistics.

Strikingly, Rochman says, only one well-designed study failed to find the effect it was looking for, an investigation of mussels ingesting microscopic bits. The plastic moved from the mussels’ stomachs to their bloodstreams, scientists found, and stayed there for weeks – but didn’t seem to stress out the shellfish.

While mussels may be fine eating trash, though, the analysis also gave a clearer picture of the many ways that ocean debris is bothersome.

Within the studies they looked at, most of the proven threats came from plastic debris, rather than other materials like metal or wood. Most of the dangers also involved large pieces of debris – animals getting entangled in trash, for example, or eating it and severely injuring themselves.

But a lot of ocean debris is ‘microplastic’, or pieces smaller than five millimeters. These may be ingredients used in cosmetics and toiletries, fibers shed by synthetic clothing in the wash, or eroded remnants of larger debris. Compared to the number of studies investigating large-scale debris, Rochman’s group found little research on the effects of these tiny bits. ‘There are a lot of open questions still for microplastic,’ Rochman says, though she notes that more papers on the subject have been published since 2013, the cutoff point for the group’s analysis.

There are also, she adds, a lot of open questions about the ways that ocean debris can lead to sea-creature death. Many studies have looked at how plastic affects an individual animal, or that animal’s tissues or cells, rather than whole populations. And in the lab, scientists often use higher concentrations of plastic than what’s really in the ocean. None of that tells us how many birds or fish or sea turtles could die from plastic pollution – or how deaths in one species could affect that animal’s predators, or the rest of the ecosystem.

‘We need to be asking more ecologically relevant questions,’ Rochman says. Usually, scientists don’t know exactly how disasters such as a tanker accidentally spilling its whole cargo of oil and polluting huge areas of the ocean will affect the environment until after they’ve happened. ‘We don’t ask the right questions early enough,’ she says. But if ecologists can understand how the slow-moving effect of ocean trash is damaging ecosystems, they might be able to prevent things from getting worse.

Asking the right questions can help policy makers, and the public, figure out where to focus their attention. The problems that look or sound most dramatic may not be the best places to start. For example, the name of the ‘Great Pacific Garbage Patch’ – a collection of marine debris in the northern Pacific Ocean – might conjure up a vast, floating trash island. In reality though, much of the debris is tiny or below the surface; a person could sail through the area without seeing any trash at all. A Dutch group called ‘The Ocean Cleanup’ is currently working on plans to put mechanical devices in the Pacific Garbage Patch and similar areas to suck up plastic. But a recent paper used simulations to show that strategically positioning the cleanup devices closer to shore would more effectively reduce pollution over the long term.

‘I think clearing up some of these misperceptions is really important,’ Rochman says. Among scientists as well as in the media, she says, ‘A lot of the images about strandings and entanglement and all of that cause the perception that plastic debris is killing everything in the ocean.’ Interrogating the existing scientific literature can help ecologists figure out which problems really need addressing, and which ones they’d be better off – like the mussels – absorbing and ignoring.

Questions 27-33
Do the following statements agree with the information given in Reading Passage 3? In boxes 27-33 on you 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

27. Rochman and her colleagues were the first people to research the problem of marine debris.

28. The creatures most in danger from ocean trash are certain seabirds.

29. The studies Rochman has reviewed have already proved that populations of some birds will soon become extinct.

30. Rochman analysed papers on the different kinds of danger caused by ocean trash.

31. Most of the research analysed by Rochman and her colleagues was badly designed.

32. One study examined by Rochman was expecting to find that mussels were harmed by eating plastic.

33. Some mussels choose to eat plastic in preference to their natural diet.

Questions 34-39
Complete the notes below. Choose ONE WORD ONLY from the passage for each answer. Write your answers in boxes 34-39 on your answer sheet.

Findings related to marine debris

Studies of marine debris found the biggest threats were

  • plastic (not metal or wood)
  • bits of debris that were 34………………………….. (harmful to animals)

There was little research into 35…………………………. e.g. from synthetic fibres.

Drawbacks of the studies examined

  • most of them focused on individual animals, not entire 36 ………………………..
  • the 37…………………….. of plastic used in the lab did not always reflect those in the ocean
  • there was insufficient information on
    • numbers of animals which could be affected
    • the impact of a reduction in numbers on the 38……………………….. of that species
    • the impact on the ecosystem

Rochman says more information is needed on the possible impact of future 39………………………… (e.g. involving oil).

Question 40
Choose the correct letter, A, B, C or D. Write the correct letter in box 40 on your answer sheet.

40. What would be the best title for this passage?

A. Assessing the threat of marine debris

B. Marine debris: who is to blame?

C. A new solution to the problem of marine debris

D. Marine debris: the need for international action

45. Bài 45

Nutmeg – a valuable spice

The nutmeg tree, Myristica fragrans, is a large evergreen tree native to Southeast Asia. Until the late 18th century, it only grew in one place in the world: a small group of islands in the Banda Sea, part of the Moluccas – or Spice Islands – in northeastern Indonesia. The tree is thickly branched with dense foliage of tough, dark green oval leaves, and produces small, yellow, bell-shaped flowers and pale yellow pear-shaped fruits. The fruit is encased in a flesh husk. When the fruit is ripe, this husk splits into two halves along a ridge running the length of the fruit. Inside is a purple-brown shiny seed, 2-3 cm long by about 2 cm across, surrounded by a lacy red or crimson covering called an ‘aril’. These are the sources of the two spices nutmeg and mace, the former being produced from the dried seed and the latter from the aril.

Nutmeg was a highly prized and costly ingredient in European cuisine in the Middle Ages, and was used as a flavouring, medicinal, and preservative agent. Throughout this period, the Arabs were the exclusive importers of the spice to Europe. They sold nutmeg for high prices to merchants based in Venice, but they never revealed the exact location of the source of this extremely valuable commodity. The Arab-Venetian dominance of the trade finally ended in 1512, when the Portuguese reached the Banda Islands and began exploiting its precious resources.

Always in danger of competition from neighbouring Spain, the Portuguese began subcontracting their spice distribution to Dutch traders. Profits began to flow into the Netherlands, and the Dutch commercial fleet swiftly grew into one of the largest in the world. The Dutch quietly gained control of most of the shipping and trading of spices in Northern Europe. Then, in 1580, Portugal fell under Spanish rule, and by the end of the 16th century the Dutch found themselves locked out of the market. As prices for pepper, nutmeg, and other spices soared across Europe, they decided to fight back.

In 1602, Dutch merchants founded the VOC, a trading corporation better known as the Dutch East India Company. By 1617, the VOC was the richest commercial operation in the world. The company had 50,000 employees worldwide, with a private army of 30,000 men and a fleet of 200 ships. At the same time, thousands of people across Europe were dying of the plague, a highly contagious and deadly disease. Doctors were desperate for a way to stop the spread of this disease, and they decided nutmeg held the cure. Everybody wanted nutmeg, and many were willing to spare no expense to have it. Nutmeg bought for a few pennies in Indonesia could be sold for 68,000 times its original cost on the streets of London. The only problem was the short supply. And that’s where the Dutch found their opportunity.

The Banda Islands were ruled by local sultans who insisted on maintaining a neutral trading policy towards foreign powers. This allowed them to avoid the presence of Portuguese or Spanish troops on their soil, but it also left them unprotected from other invaders. In 1621, the Dutch arrived and took over. Once securely in control of the Bandas, the Dutch went to work protecting their new investment. They concentrated all nutmeg production into a few easily guarded areas, uprooting and destroying any trees outside the plantation zones. Anyone caught growing a nutmeg seedling or carrying seeds without the proper authority was severely punished. In addition, all exported nutmeg was covered with lime to make sure there was no chance a fertile seed which could be grown elsewhere would leave the islands. There was only one obstacle to Dutch domination. One of the Banda Islands, a sliver of land called Run, only 3 km long by less than 1 km wide, was under the control of the British. After decades of fighting for control of this tiny island, the Dutch and British arrived at a compromise settlement, the Treaty of Breda, in 1667. Intent on securing their hold over every nutmeg-producing island, the Dutch offered a trade: if the British would give them the island of Run, they would in turn give Britain a distant and much less valuable island in North America. The British agreed. That other island was Manhattan, which is how New Amsterdam became New York. The Dutch now had a monopoly over the nutmeg trade which would last for another century.
Then, in 1770, a Frenchman named Pierre Poivre successfully smuggled nutmeg plants to safety in Mauritius, an island off the coast of Africa. Some of these were later exported to the Caribbean where they thrived, especially on the island of Grenada. Next, in 1778, a volcanic eruption in the Banda region caused a tsunami that wiped out half the nutmeg groves. Finally, in 1809, the British returned to Indonesia and seized the Banda Islands by force. They returned the islands to the Dutch in 1817, but not before transplanting hundreds of nutmeg seedlings to plantations in several locations across southern Asia. The Dutch nutmeg monopoly was over.

Today, nutmeg is grown in Indonesia, the Caribbean, India, Malaysia, Papua New Guinea and Sri Lanka, and world nutmeg production is estimated to average between 10,000 and 12,000 tonnes per year.

Questions 1-4
Complete the notes below. Choose ONE WORD ONLY from the passage for each answer. Write your answers in boxes 1-4 on your answer sheet.

The nutmeg tree and fruit

  • the leaves of the tree are 1……………………. in shape
  • the 2……………………. surrounds the fruit and breaks open when the fruit is ripe
  • the 3……………………. is used to produce the spice nutmeg
  • the covering known as the aril is used to produce 4……………………..
  • the tree has yellow flowers and fruit

Questions 5-7
Do the following statements agree with the information given in Reading Passage 1? In boxes 5-7 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

5. In the Middle Ages, most Europeans knew where nutmeg was grown.

6. The VOC was the world’s first major trading company.

7. Following the Treaty of Breda, the Dutch had control of all the islands where nutmeg grew.

Questions 8-13
Complete the table below. Choose ONE WORD ONLY from the passage for each answer. Write your answers in boxes 8-13 on your answer sheet.

Nutmeg – a valuable spice

46. Bài 46

Should we try to bring extinct species back to life?

A. The passenger pigeon was a legendary species. Flying in vast numbers across North America, with potentially many millions within a single flock, their migration was once one of nature’s great spectacles. Sadly, the passenger pigeon’s existence came to an end on 1 September 1914, when the last living specimen died at Cincinnati Zoo. Geneticist Ben Novak is lead researcher on an ambitious project which now aims to bring the bird back to life through a process known as ‘de-extinction’. The basic premise involves using cloning technology to turn the DNA of extinct animals into a fertilised embryo, which is carried by the nearest relative still in existence – in this case, the abundant band-tailed pigeon – before being born as a living, breathing animal. Passenger pigeons are one of the pioneering species in this field, but they are far from the only ones on which this cutting-edge technology is being trialled.

B. In Australia, the thylacine, more commonly known as the Tasmanian tiger, is another extinct creature which genetic scientists are striving to bring back to life. ‘There is no carnivore now in Tasmania that fills the niche which thylacines once occupied,’ explains Michael Archer of the University of New South Wales. He points out that in the decades since the thylacine went extinct, there has been a spread in a ‘dangerously debilitating’ facial tumour syndrome which threatens the existence of the Tasmanian devils, the island’s other notorious resident. Thylacines would have prevented this spread because they would have killed significant numbers of Tasmanian devils. ‘If that contagious cancer had popped up previously, it would have burned out in whatever region it started. The return of thylacines to Tasmania could help to ensure that devils are never again subjected to risks of this kind.’

C. If extinct species can be brought back to life, can humanity begin to correct the damage it has caused to the natural world over the past few millennia? ‘The idea of de-extinction is that we can reverse this process, bringing species that no longer exist back to life,’ says Beth Shapiro of University of California Santa Cruz’s Genomics Institute. ‘I don’t think that we can do this. There is no way to bring back something that is 100 per cent identical to a species that went extinct a long time ago.’ A more practical approach for long-extinct species is to take the DNA of existing species as a template, ready for the insertion of strands of extinct animal DNA to create something new; a hybrid, based on the living species, but which looks and/or acts like the animal which died out.

D. This complicated process and questionable outcome begs the question: what is the actual point of this technology? ‘For us, the goal has always been replacing the extinct species with a suitable replacement,’ explains Novak. ‘When it comes to breeding, band-tailed pigeons scatter and make maybe one or two nests per hectare, whereas passenger pigeons were very social and would make 10,000 or more nests in one hectare.’ Since the disappearance of this key species, ecosystems in the eastern US have suffered, as the lack of disturbance caused by thousands of passenger pigeons wrecking trees and branches means there has been minimal need for regrowth. This has left forests stagnant and therefore unwelcoming to the plants and animals which evolved to help regenerate the forest after a disturbance. According to Novak, a hybridized band-tailed pigeon, with the added nesting habits of a passenger pigeon, could, in theory, re-establish that forest disturbance, thereby creating a habitat necessary for a great many other native species to thrive.

E. Another popular candidate for this technology is the woolly mammoth. George Church, professor at Harvard Medical School and leader of the Woolly Mammoth Revival Project, has been focusing on cold resistance, the main way in which the extinct woolly mammoth and its nearest living relative, the Asian elephant, differ. By pinpointing which genetic traits made it possible for mammoths to survive the icy climate of the tundra, the project’s goal is to return mammoths, or a mammoth-like species, to the area. ‘My highest priority would be preserving the endangered Asian elephant,’ says Church, ‘expanding their range to the huge ecosystem of the tundra. Necessary adaptations would include smaller ears, thicker hair, and extra insulating fat, all for the purpose of reducing heat loss in the tundra, and all traits found in the now extinct woolly mammoth.’ This repopulation of the tundra and boreal forests of Eurasia and North America with large mammals could also be a useful factor in reducing carbon emissions – elephants punch holes through snow and knock down trees, which encourages grass growth. This grass growth would reduce temperature, and mitigate emissions from melting permafrost.

F. While the prospect of bringing extinct animals back to life might capture imaginations, it is, of course, far easier to try to save an existing species which is merely threatened with extinction. ‘Many of the technologies that people have in mind when they think about de-extinction can be used as a form of “genetic rescue”,’ explains Shapiro. She prefers to focus the debate on how this emerging technology could be used to fully understand why various species went extinct in the first place, and therefore how we could use it to make genetic modifications which could prevent mass extinctions in the future. ‘I would also say there’s an incredible moral hazard to not do anything at all,’ she continues. ‘We know that what we are doing today is not enough, and we have to be willing to take some calculated and measured risks.’

Questions 14-17
Reading Passage 2 has six paragraphs, A-F.

Which paragraph contains the following information?

Write the correct letter, A-F, in boxes 14-17 on your answer sheet.

NB You may use any letter more than once.
14. a reference to how further disappearance of multiple species could be avoided.

15. explanation of a way of reproducing an extinct animal using the DNA of only that species
16. reference to a habitat which has suffered following the extinction of a species
17. mention of the exact point at which a particular species became extinct

Questions 18-22
Complete the summary below. Choose NO MORE THAN TWO WORDS from the passage for each answer. Write your answers in boxes 18-22 on your answer sheet.

The woolly mammoth revival project

Professor George Church and his team are trying to identify the 18…………………… which enabled mammoths to live in the tundra. The findings could help preserve the mammoth’s close relative, the endangered Asian elephant.

According to Church, introducing Asian elephants to the tundra would involve certain physical adaptations to minimise 19…………………… To survive in the tundra, the species would need to have the mammoth-like features of thicker hair, 20………………….. of a reduced size and more 21……………………..

Repopulating the tundra with mammoths or Asian elephant/mammoth hybrids would also have an impact on the environment, which could help to reduce temperatures and decrease 22……………………

Questions 23-26
Look at the following statements (Questions 23-26) and the list of people below. Match each statement with the correct person, A, B or C. Write the correct letter, A, B or C, in boxes 23-26 on your answer sheet.

NB You may use any letter more than once.
23. Reintroducing an extinct species to its original habitat could improve the health of a particular species living there.

24. It is important to concentrate on the causes of an animal’s extinction.

25. A species brought back from extinction could have an important beneficial impact on the vegetation of its habitat.

26. Our current efforts at preserving biodiversity are insufficient.

List of People

A. Ben Novak

B. Michael Archer

C. Beth Shapiro

47. Bài 47

Questions 14-20
Reading Passage 2 has nine paragraphs, A-H. Choose the correct heading for each section from the list of headings below Write the correct number, i-x, in boxes 14-20 on your answer sheet.

List of Headings

i. Getting the finance for production

ii. An unexpected benefit

iii. From initial inspiration to new product

iv. The range of potential customers for the device
v. What makes the device different from alternatives

vi. Cleaning water from a range of sources

vii. Overcoming production difficulties

viii. Profit not the primary goal

ix. A warm welcome for the device

x. The number of people affected by water shortages
14. Section A

15. Section B

16. Section C

17. Section D

18. Section E

19. Section F

20. Section G

The Desolenator: producing clean water

A. Travelling around Thailand in the 1990s, William Janssen was impressed with the basic rooftop solar heating systems that were on many homes, where energy from the sun was absorbed by a plate and then used to heat water for domestic use. Two decades later Janssen developed that basic idea he saw in Southeast Asia into a portable device that uses the power from the sun to purify water.

B. The Desolenator operates as a mobile desalination unit that can take water from different places, such as the sea, rivers, boreholes and rain, and purify it for human consumption. It is particularly valuable in regions where natural groundwater reserves have been polluted, or where seawater is the only water source available.

Janssen saw that there was a need for a sustainable way to clean water is both the developing and the developed countries when he moved to the United Arab Emirates and saw large-scale water processing. ‘I was confronted with the enormous carbon footprint that the Gulf nations have because of all of the desalination that they do,’ he says.

C. The Desolenator can produce 15 litres of drinking water per day, enough to sustain a family for cooking and drinking. Its main selling point is that unlike standard desalination techniques, it doesn’t require a generated power supply: just sunlight. It measures 120 cm by 90 cm, and it easy to transport, thanks to its two wheels. Water enters through a pipe, and flows as a thin film between a sheet of double glazing and the surface of a solar panel, where it is heated by the sun. the warm water flows into a small boiler (heated by a solar-powered battery) where it is converted to steam. When the steam cools, it becomes distilled water. The device has a very simple filter to trap particles, and this can easily be shaken to remove them. There are two tubes for liquid coming out: one for the waste – salt from seawater, fluoride, etc. – and another for the distilled water. The performance of the unit is shown on an LCD screen and transmitted to the company which provides servicing when necessary.

D. A recent analysis found that at least two-thirds of the world’s population lives with severe water scarcity for at least a month every year. Janssen says that be 2030 half of the world’s population will be living with water stress – where the demand exceeds the supply over a certain period of time. ‘It is really important that a sustainable solution is brought to the market that is able to help these people,’ he says. Many countries ‘don’t have the money for desalination plants, which are very expensive to build. They don’t have the money to operate them, they are very maintenance intensive, and they don’t have the money to buy the diesel to run the desalination plants, so it is a really bad situation.’

E. The device is aimed at a wide variety of users – from homeowners in the developing world who do not have a constant supply of water to people living off the grid in rural parts of the US. The first commercial versions of the Desolenator are expected to be in operation in India early next year, after field tests are carried out. The market for the self-sufficient devices in developing countries is twofold – those who cannot afford the money for the device outright and pay through microfinance, and middle-income homes that can lease their own equipment. ‘People in India don’t pay for a fridge outright; they pay for it over six months. They would put the Desolenator on their roof and hook it up to their municipal supply and they would get very reliable drinking water on a daily basis,’ Janssen says. In the developed world, it is aimed at niche markets where tap water is unavailable – for camping, on boats, or for the military, for instance.

F. Prices will vary according to where it is bought. In the developing world, the price will depend on what deal aid organisations can negotiate. In developed countries, it is likely to come in at $1,000 (£685) a unit, said Janssen. ‘We are a venture with a social mission. We are aware that the product we have envisioned is mainly finding application in the developing world and humanitarian sector and that this is the way we will proceed. We do realise, though, that to be a viable company there is a bottom line to keep in mind,’ he says.

G. The company itself is based at Imperial College London, although Janssen, its chief executive, still lives in the UAE. It has raised £340,000 in funding so far. Within two years, he says, the company aims to be selling 1,000 units a month, mainly in the humanitarian field. They are expected to be sold in areas such as Australia, northern Chile, Peru, Texas and California.

Questions 21-26
Complete the summary below. Choose ONE WORD ONLY from the passage for each answer. Write your answers in boxes 21-26 on your answer sheet.

How the Desolenator works

The energy required to operate the Desolenator comes from sunlight. The device can be used in different locations, as it has 21…………… . Water is fed into a pipe, and a 22……….. of water flows over a solar panel. The water then enters a boiler, where it turns into steam. Any particles in the water are caught in a 23………… . The purified water comes out through one tube, and all types of 24……………… come out through another. A screen displays the 25…………… of the device, and transmits the information to the company so that they know when the Desolenator requires 26……………. .

48. Bài 48

The return of the huarango

The arid valleys of southern Peru are welcoming the return of a native plant

The south coast of Peru is a narrow, 2,000-kilometre-long strip of desert squeezed between the Andes and the Pacific Ocean. It is also one of the most fragile ecosystems on Earth. It hardly ever rains there, and the only year-round source of water is located tens of metres below the surface. This is why the huarango tree is so suited to life there: it has the longest roots of any tree in the world. They stretch down 50-80 metres and, as well as sucking up water for the tree, they bring it into the higher subsoil, creating a water source for other plant life.

Dr David Beresford-Jones, archaeobotanist at Cambridge University, has been studying the role of the huarango tree in landscape change in the Lower Ica Valley in southern Peru. He believes the huarango was key to the ancient people’s diet and, because it could reach deep water sources, it allowed local people to withstand years of drought when their other crops failed. But over the centuries huarango trees were gradually replaced with crops. Cutting down native woodland leads to erosion, as there is nothing to keep the soil in place. So when the huarangos go, the land turns into a desert. Nothing grows at all in the Lower Ica Valley now.

For centuries the huarango tree was vital to the people of the neighbouring Middle Ica Valley too. They grew vegetables under it and ate products made from its seed pods. Its leaves and bark were used for herbal remedies, while its branches were used for charcoal for cooking and heating, and its trunk was used to build houses. But now it is disappearing rapidly. The majority of the huarango forests in the valley have already been cleared for fuel and agriculture – initially, these were smallholdings, but now they’re huge farms producing crops for the international market.

‘Of the forests that were here 1,000 years ago, 99 per cent have already gone,’ says botanist Oliver Whaley from Kew Gardens in London, who, together with ethnobotanist Dr William Milliken, is running a pioneering project to protect and restore the rapidly disappearing habitat. In order to succeed, Whaley needs to get the local people on board, and that has meant overcoming local prejudices. ‘Increasingly aspirational communities think that if you plant food trees in your home or street, it shows you are poor, and still need to grow your own food,’ he says. In order to stop the Middle Ica Valley going the same way as the Lower Ica Valley, Whaley is encouraging locals to love the huarangos again. ‘It’s a process of cultural resuscitation,’ he says. He has already set up a huarango festival to reinstate a sense of pride in their eco-heritage, and has helped local schoolchildren plant thousands of trees.

‘In order to get people interested in habitat restoration, you need to plant a tree that is useful to them,’ says Whaley. So, he has been working with local families to attempt to create a sustainable income from the huarangos by turning their products into foodstuffs. ‘Boil up the beans and you get this thick brown syrup like molasses. You can also use it in drinks, soups or stews.’ The pods can be ground into flour to make cakes, and the seeds roasted into a sweet, chocolatey ‘coffee’. ‘It’s packed full of vitamins and minerals,’ Whaley says.

And some farmers are already planting huarangos. Alberto Benevides, owner of Ica Valley’s only certified organic farm, which Whaley helped set up, has been planting the tree for 13 years. He produces syrup and flour, and sells these products at an organic farmers’ market in Lima. His farm is relatively small and doesn’t yet provide him with enough to live on, but he hopes this will change. ‘The organic market is growing rapidly in Peru,’ Benevides says. ‘I am investing in the future.’

But even if Whaley can convince the local people to fall in love with the huarango again, there is still the threat of the larger farms. Some of these cut across the forests and break up the corridors that allow the essential movement of mammals, birds and pollen up and down the narrow forest strip. In the hope of counteracting this, he’s persuading farmers to let him plant forest corridors on their land. He believes the extra woodland will also benefit the farms by reducing their water usage through a lowering of evaporation and providing a refuge for bio-control insects.

‘If we can record biodiversity and see how it all works, then we’re in a good position to move on from there. Desert habitats can reduce down to very little,’ Whaley explains. ‘It’s not like a rainforest that needs to have this huge expanse. Life has always been confined to corridors and islands here. If you just have a few trees left, the population can grow up quickly because it’s used to exploiting water when it arrives.’ He sees his project as a model that has the potential to be rolled out across other arid areas around the world. ‘If we can do it here, in the most fragile system on Earth, then that’s a real message of hope for lots of places, including Africa, where there is drought and they just can’t afford to wait for rain.’

 

Questions 1-5
Complete the notes below. Choose ONE WORD ONLY from the passage for each answer. Write your answer in boxes 1-5 on your answer sheet.

The importance of the huarango tree

– its roots can extend as far as 80 metres into the soil

– can access 1………………… deep below the surface

– was a crucial part of local inhabitants’ 2………………… a long time ago

– helped people to survive periods of 3…………………..

– prevents 4………………… of the soil

– prevents land from becoming a 5…………………

Questions 6-8
Complete the table below. Choose NO MORE THAN TWO WORDS from the passage for each answer. Write your answers in boxes 6-8 on your answer sheet

The return of the huarango

Questions 9-13
Do the following statements agree with the information given in Reading Passage 1? In boxes 9-13 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
9. Local families have told Whaley about some traditional uses of huarango products.

10. Farmer Alberto Benevides is now making a good profit from growing huarangos.

11. Whaley needs the co-operation of farmers to help preserve the area’s wildlife.

12. For Whaley’s project to succeed, it needs to be extended over a very large area.

13. Whaley has plans to go to Africa to set up a similar project.

49. Bài 49

Silbo Gomero – the whistle ‘language’ of the Canary Islands

La Gomera is one of the Canary Islands situated in the Atlantic Ocean off the northwest coast of Africa. This small volcanic island is mountainous, with steep rocky slopes and deep, wooded ravines, rising to 1,487 metres at its highest peak. It is also home to the best known of the world’s whistle ‘languages’, a means of transmitting information over long distances which is perfectly adapted to the extreme terrain of the island.

This ‘language’, known as ‘Silbo’ or ‘Silbo Gomero’ – from the Spanish word for ‘whistle’ – is now shedding light on the language-processing abilities of the human brain, according to scientists. Researchers say that Silbo activates parts of the brain normally associated with spoken language, suggesting that the brain is remarkably flexible in its ability to interpret sounds as language.

‘Science has developed the idea of brain areas that are dedicated to language, and we are starting to understand the scope of signals that can be recognised as language,’ says David Corina, co-author of a recent study and associate professor of psychology at the University of Washington in Seattle.

Silbo is a substitute for Spanish, with individual words recoded into whistles which have high- and low-frequency tones. A whistler – or silbador – puts a finger in his or her mouth to increase the whistle’s pitch, while the other hand can be cupped to adjust the direction of the sound. ‘There is much more ambiguity in the whistled signal than in the spoken signal,’ explains lead researcher Manuel Carreiras, psychology professor at the University of La Laguna on the Canary island of Tenerife. Because whistled ‘words’ can be hard to distinguish, silbadores rely on repetition, as well as awareness of context, to make themselves understood.

The silbadores of Gomera are traditionally shepherds and other isolated mountain folk, and their novel means of staying in touch allows them to communicate over distances of up to 10 kilometres. Carreiras explains that silbadores are able to pass a surprising amount of information via their whistles. ‘In daily life they use whistles to communicate short commands, but any Spanish sentence could be whistled.’ Silbo has proved particularly useful when fires have occurred on the island and rapid communication across large areas has been vital.

The study team used neuroimaging equipment to contrast the brain activity of silbadores while listening to whistled and spoken Spanish. Results showed the left temporal lobe of the brain, which is usually associated with spoken language, was engaged during the processing of Silbo. The researchers found that other key regions in the brain’s frontal lobe also responded to the whistles, including those activated in response to sign language among deaf people. When the experiments were repeated with non-whistlers, however, activation was observed in all areas of the brain.
‘Our results provide more evidence about the flexibility of human capacity for language in a variety of forms,’ Corina says. ‘These data suggest that left-hemisphere language regions are uniquely adapted for communicative purposes, independent of the modality of signal. The non-Silbo speakers were not recognising Silbo as a language. They had nothing to grab onto, so multiple areas of their brains were activated.’

Carreiras says the origins of Silbo Gomero remain obscure, but that indigenous Canary Islanders, who were of North African origin, already had a whistled language when Spain conquered the volcanic islands in the 15th century. Whistled languages survive today in Papua New Guinea, Mexico, Vietnam, Guyana, China, Nepal, Senegal, and a few mountainous pockets in southern Europe. There are thought to be as many as 70 whistled languages still in use, though only 12 have been described and studied scientifically. This form of communication is an adaptation found among cultures where people are often isolated from each other, according to Julien Meyer, a researcher at the Institute of Human Sciences in Lyon, France. ‘They are mostly used in mountains or dense forests,’ he says. ‘Whistled languages are quite clearly defined and represent an original adaptation of the spoken language for the needs of isolated human groups.’

But with modern communication technology now widely available, researchers say whistled languages like Silbo are threatened with extinction. With dwindling numbers of Gomera islanders still fluent in the language, Canaries’ authorities are taking steps to try to ensure its survival. Since 1999, Silbo Gomero has been taught in all of the island’s elementary schools. In addition, locals are seeking assistance from the United Nations Educational, Scientific and Cultural Organization (UNESCO). ‘The local authorities are trying to get an award from the organisation to declare [Silbo Gomero] as something that should be preserved for humanity,’ Carreiras adds.

Questions 14-19
Do the following statements agree with the information given in Reading Passage 2? In boxes 14-19 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
14. La Gomera is the most mountainous of all the Canary Islands.

15. Silbo is only appropriate for short and simple messages.
16. In the brain-activity study, silbadores and non-whistlers produced different results.
17. The Spanish introduced Silbo to the islands in the 15th century.

18. There is precise data available regarding all of the whistle languages in existence today.

19. The children of Gomera now learn Silbo.

Questions 18-22
Complete the notes below. Choose ONE WORD ONLY from the passage for each answer. Write your answers in boxes 20-26 on your answer sheet.

Silbo Gomero

How Silbo is produced

  • high- and low-frequency tones represent different sounds in Spanish 20……………
  • pitch of whistle is controlled using silbador’s 21……………
  • 22………….. is changed with a cupped hand

How Silbo is used

  • has long been used by shepherds and people living in secluded locations
  • in everyday use for the transmission of brief 23……………
  • can relay essential information quickly, e.g. to inform people about 24……………

The future of Silbo

  • future under threat because of new 25……………
  • Canaries’ authorities hoping to receive a UNESCO 26……………. to help preserve it

50. Bài 50

Why we need to protect polar bears

Polar bears are being increasingly threatened by the effects of climate change, but their disappearance could have far-reaching consequences. They are uniquely adapted to the extreme conditions of the Arctic Circle, where temperatures can reach -40°C. One reason for this is that they have up to 11 centimetres of fat underneath their skin. Humans with comparative levels of adipose tissue would be considered obese and would be likely to suffer from diabetes and heart disease. Yet the polar bear experiences no such consequences.

A 2014 study by Shi Ping Liu and colleagues sheds light on this mystery. They compared the genetic structure of polar bears with that of their closest relatives from a warmer climate, the brown bears. This allowed them to determine the genes that have allowed polar bears to survive in one of the toughest environments on Earth. Liu and his colleagues found the polar bears had a gene known as APoB, which reduces levels of low-density lipoproteins (LDLs) – a form of ‘bad’ cholesterol. In humans, mutations of this gene are associated with increased risk of heart disease. Polar bears may therefore be an important study model to understand heart disease in humans.
The genome of the polar bear may also provide the solution for another condition, one that particularly affects our older generation: osteoporosis. This is a disease where bones show reduced density, usually caused by insufficient exercise, reduced calcium intake or food starvation. Bone tissue is constantly being remodelled, meaning that bone is added or removed, depending on nutrient availability and the stress that the bone is under. Female polar bears, however, undergo extreme conditions during every pregnancy. Once autumn comes around, these females will dig maternity dens in the snow and will remain there throughout the winter, both before and after the birth of their cubs. This process results in about six months of fasting, where the female bears have to keep themselves and their cubs alive, depleting their own calcium and calorie reserves. Despite this, their bones remain strong and dense.
Physiologists Alanda Lennox and Allen Goodship found an explanation for this paradox in 2008. They discovered that pregnant bears were able to increase the density of their bones before they started to build their dens. In addition, six months later, when they finally emerged from the den with their cubs, there was no evidence of significant loss of bone density. Hibernating brown bears do not have this capacity and must therefore resort to major bone reformation in the following spring. If the mechanism of bone remodelling in polar bears can be understood, many bedridden humans, and even astronauts, could potentially benefit.

The medical benefits of the polar bear for humanity certainly have their importance in our conservation efforts, but these should not be the only factors taken into consideration. We tend to want to protect animals we think are intelligent and possess emotions, such as elephants and primates. Bears, on the other hand, seem to be perceived as stupid and in many cases violent. And yet anecdotal evidence from the field challenges those assumptions, suggesting for example that polar bears have good problem-solving abilities. A male bear called GoGo in Tennoji Zoo, Osaka, has even been observed making use of a tool to manipulate his environment. The bear used a tree branch on multiple occasions to dislodge a piece of meat hung out of his reach. Problem-solving ability has also been witnessed in wild polar bears, although not as obviously as with GoGo. A calculated move by a male bear involved running and jumping onto barrels in an attempt to get to a photographer standing on a platform four metres high.
In other studies, such as one by Alison Ames in 2008, polar bears showed deliberate and focused manipulation. For example, Ames observed bears putting objects in piles and then knocking them over in what appeared to be a game. The study demonstrates that bears are capable of agile and thought-out behaviours. These examples suggest bears have greater creativity and problem-solving abilities than previously thought.

As for emotions, while the evidence is once again anecdotal, many bears have been seen to hit out at ice and snow – seemingly out of frustration – when they have just missed out on a kill. Moreover, polar bears can form unusual relationships with other species, including playing with the dogs used to pull sleds in the Arctic. Remarkably, one hand-raised polar bear called Agee has formed a close relationship with her owner Mark Dumas to the point where they even swim together. This is even more astonishing since polar bears are known to actively hunt humans in the wild.

If climate change were to lead to their extinction, this would mean not only the loss of potential breakthroughs in human medicine, but more importantly, the disappearance of an intelligent, majestic animal.

Questions 1-7
Do the following statements agree with the information given in Reading Passage 1? In boxes 1-7 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. Polar bears suffer from various health problems due to the build-up of fat under their skin.

2. The study done by Liu and his colleagues compared different groups of polar bears.

3. Liu and colleagues were the first researchers to compare polar bears and brown bears genetically.

4. Polar bears are able to control their levels of ‘bad’ cholesterol by genetic means.
5. Female polar bears are able to survive for about six months without food.
6. It was found that the bones of female polar bears were very weak when they came out of their dens in spring.

7. The polar bear’s mechanism for increasing bone density could also be used by people one day.

Questions 8-13
Complete the table below. Choose ONE WORD ONLY from the passage for each answer. Write your answers in boxes 8-13 on your answer sheet.

Reasons why polar bears should be protected

People think of bears as unintelligent and 8 ………………. .
However, this may not be correct. For example:

  • In Tennoji Zoo, a bear has been seen using a branch as a 9 ……. . This allowed him to knock down some 10 ……. .
  • A wild polar bear worked out a method of reaching a platform where a 11 ………………. was located.
  • Polar bears have displayed behaviour such as conscious manipulation of objects and activity similar to a 12 ……. .

Bears may also display emotions. For example:

  • They may make movements suggesting 13 ………………. if disappointed when hunting.
  • They may form relationships with other species.

51. Bài 51

The White Horse of Uffington

The cutting of huge figures or ‘geoglyphs’ into the earth of English hillsides has taken place for more than 3,000 years. There are 56 hill figures scattered around England, with the vast majority on the chalk downlands of the country’s southern counties. The figures include giants, horses, crosses and regimental badges. Although the majority of these geoglyphs date within the last 300 years or so, there are one or two that are much older.

The most famous of these figures is perhaps also the most mysterious – the Uffington White Horse in Oxfordshire. The White Horse has recently been re-dated and shown to be even older than its previously assigned ancient pre-Roman Iron Age* date. More cont