IELTS Academic Reading Practice Test 16

READING PASSAGE 1

You should spend about 20 minutes on Questions 1–13, which are based on Reading Passage 1 below.

The city of stone: Great Zimbabwe

A In the hills of south-eastern Zimbabwe, about 30 kilometres from the modern town of Masvingo, stand the remains of the largest ancient stone city in southern Africa. Great Zimbabwe was built and occupied between roughly the eleventh and fifteenth centuries by the ancestors of the Shona people, who still make up the majority of the country's population. Its name comes from the Shona phrase dzimba dza mabwe, usually translated as "houses of stone". When the country gained its independence in 1980, it chose to take its name from the site, and a soapstone bird found among the ruins appears on the national flag. In 1986, Great Zimbabwe was declared a World Heritage Site.

B The ruins cover an area of around seven square kilometres and are usually divided into three groups. The oldest, known as the Hill Complex, sits on top of a granite hill and makes use of the huge natural boulders there, with walls built to join one rock to the next. Below it, in the valley, lie the Valley Ruins, a collection of smaller enclosures that were added over several centuries. The most impressive structure, however, is the Great Enclosure. Its outer wall is about 250 metres long and up to 11 metres high, and at its base it is around five metres thick. Inside, a narrow passage runs between the outer wall and an inner wall, leading to a solid stone tower about ten metres tall. The tower has no entrance and no rooms, and its purpose remains uncertain: it may have been a symbol of a ruler's wealth, perhaps representing a grain store, or it may have had a religious meaning.

C What makes the walls particularly remarkable is the way they were built. The builders used no mortar to hold the stones together. Instead, they relied on the natural properties of the local granite, which tends to split into flat layers as its surface is heated by the sun and cools at night. By lighting fires against the rock, workers could speed up this process and remove slabs that were then broken into neat blocks of a similar size. These were laid in careful horizontal rows, with each wall slightly narrower at the top than at the bottom, which made it more stable. The finest walls of the Great Enclosure are decorated near the top with a chevron pattern, a line of stones set at an angle to form a series of V shapes.

D At its height, in the thirteenth and fourteenth centuries, Great Zimbabwe may have been home to as many as 18,000 people, although estimates vary considerably. Most of them lived in round houses made of a mud-based material called daga, outside the stone walls. The stone enclosures themselves seem to have been reserved for the ruler, his family and other important people. The city's wealth was based partly on cattle, but it also controlled an important trade in gold, which was mined further west and carried to towns on the East African coast. Excavations have produced objects from far beyond Africa: glass beads from India, pottery from Persia, and fragments of Chinese porcelain. A copper coin from the coastal city of Kilwa, in what is now Tanzania, shows how far the city's connections reached.

E Yet for much of the twentieth century, the people who built Great Zimbabwe were not given credit for it. When the German explorer Karl Mauch reached the site in 1871, he concluded that it could not have been built by Africans, and suggested that it was a copy of a palace of the Queen of Sheba. Other writers claimed it was the work of Phoenician traders or Arabs. In 1905, the archaeologist David Randall-MacIver found that the objects at the site were African in origin and dated from the medieval period, and in 1929 Gertrude Caton-Thompson came to the same conclusion after a careful excavation. Their findings were rejected by many white settlers, however, and the white minority government of Rhodesia continued to encourage the idea of foreign builders. Guidebooks and museum displays were controlled, and some archaeologists who disagreed left the country. The claim was based not on evidence, but on the belief that Africans were incapable of such achievements.

F Great Zimbabwe was largely abandoned during the fifteenth century, and the reasons are still debated. One possibility is that the city had simply grown too large for its surroundings. A population of many thousands, with large herds of cattle, would have needed enormous amounts of grazing land, firewood and farmland, and these may have been used up over time. At the same time, the gold trade appears to have moved north, towards the Zambezi valley, where a new state, known as Mutapa, became powerful. Without its control of trade, Great Zimbabwe may have lost the wealth that had supported its rulers.

G Today, the site faces new challenges. Trees and other plants growing in and around the walls can push stones out of position, and parts of the walls have collapsed. Some early attempts at repair did more harm than good, because they used methods and materials that did not match the original building techniques, and walls were rebuilt in ways that later turned out to be inaccurate. Large numbers of visitors who climb on the walls add to the damage. Conservation teams now work with local stonemasons, some of whom have learned the traditional methods of dry-stone building, in the hope that this extraordinary place can be protected for future generations.

Questions 1–6

Reading Passage 1 has seven paragraphs, A–G.

Choose the correct heading for paragraphs B–G from the list of headings below.

Write the correct number, i–x, next to Questions 1–6.

List of Headings

• i A name chosen for a modern nation
• ii An unusual technique based on the local rock
• iii A city of three parts
• iv A wealthy city with distant contacts
• v A theory with no basis in fact
• vi Why the city was left behind
• vii Threats to the site and efforts to protect it
• viii How gold was mined at the site
• ix The discovery of a royal tomb
• x Walls that were built for defence

Example: Paragraph A — i

Questions 7–9

Choose the correct letter, A, B, C or D.

• A It was used to store grain.
• B It contained several small rooms.
• C Experts are not sure what it was for.
• D It was the oldest part of the Great Enclosure.

• A using a type of mortar.
• B making them thinner at the top.
• C using stones of different sizes.
• D adding a chevron pattern.

• A lived within the stone enclosures.
• B worked in the gold mines.
• C lived in houses made of daga.
• D owned large numbers of cattle.

Questions 10–13

Answer the questions below.

Choose NO MORE THAN TWO WORDS from the passage for each answer.

READING PASSAGE 2

You should spend about 20 minutes on Questions 14–26, which are based on Reading Passage 2 below.

Bitter truths: the science of supertasters

In 1931, a chemist named Arthur Fox was working in a laboratory in the United States when some fine powder of a chemical called phenylthiocarbamide, or PTC, blew into the air. A colleague standing nearby complained that the dust tasted extremely bitter. Fox, who was closer to the powder, could taste nothing at all. Puzzled, he asked friends and family to try the chemical, and found that people seemed to fall into two groups: those for whom PTC was unpleasantly bitter, and those who could hardly taste it. Further studies soon showed that the ability to taste PTC runs in families, and for decades the test was used in schools to teach students about inheritance.

The story might have ended there. But in the 1990s, the American researcher Linda Bartoshuk, who was studying taste at Yale University, noticed something that the earlier work had missed. Using a similar but safer chemical, known as PROP, she asked people not only whether they could taste it, but how strong the taste was. Among the "tasters", there was a smaller group who found PROP intensely, almost painfully, bitter. Bartoshuk called them "supertasters". In Bartoshuk's studies in the United States, roughly a quarter of people turned out to be supertasters, about half were medium tasters, and the remaining quarter were "non-tasters", for whom PROP had little or no taste. These proportions vary between populations, however, and women are more likely than men to be supertasters.

Part of the explanation lies in our genes. In 2003, a team of scientists identified a gene, known as TAS2R38, which carries the instructions for one of the receptors on the tongue that detect bitterness. People inherit one of several versions of this gene from each parent, and the combination they receive largely decides whether they can taste PTC and PROP. But genes are not the whole story. Bartoshuk also looked at the surface of the tongue. The small bumps that cover it, known as papillae, contain most of our taste buds. To count them, researchers paint the tip of the tongue with blue food colouring. The papillae do not take up the colour as well as the rest of the tongue, and so they appear as small pink circles that can be counted under a magnifying glass. In Bartoshuk's studies, supertasters tended to have many more papillae than non-tasters, which suggested that they simply had more taste buds.

Being a supertaster is not just a matter of bitterness. Many papillae are surrounded by nerve fibres that sense touch and pain, and supertasters seem to experience other sensations more intensely too. They often report that the burning feeling caused by chilli peppers is stronger for them, and some describe the texture of fatty foods as more creamy. In some studies, they have also rated sweet foods as sweeter, although these findings have not always been repeated.

This sensitivity has consequences for what people choose to eat. Many vegetables, particularly those in the cabbage family, such as broccoli, kale and Brussels sprouts, contain bitter compounds, and some studies have found that supertasters eat fewer of them. Supertasters are also more likely to add milk to their coffee, and to dislike grapefruit and strong alcoholic drinks. This has led to concern that supertasters might miss out on the health benefits of a diet rich in vegetables. In 2018, a study of heart patients in the United States found that supertasters were more likely than others to have a poor diet, though the researchers stressed that they could not prove that taste was the cause. On the other hand, some researchers have suggested that non-tasters, who find fewer foods unpleasant, may find it harder to resist foods that are high in fat and sugar.

The picture has become more complicated in recent years. In 2014, a study of around four hundred people found no clear link between the number of papillae on a person's tongue and how strongly they tasted PROP. This suggests that the number of taste buds may matter less than was once thought, and that differences in the brain, or in the receptors themselves, may be more important. Some scientists now argue that "supertaster" is too simple a label, because a person who is very sensitive to one bitter chemical may not be sensitive to others. Humans have around 25 different bitter receptors, and each responds to a different range of substances.

Perhaps the most surprising discovery is that these receptors are not found only on the tongue. Bitter taste receptors have been found in the nose, the throat and the lungs, where they appear to help the body respond to bacteria. In 2012, researchers in Pennsylvania showed that the receptor made by the TAS2R38 gene is present in the lining of the sinuses, the air spaces inside the face. When it detects certain chemicals released by bacteria, it triggers a defensive response. Non-tasters, who carry the non-taster version of the gene, appear to be more likely to suffer from chronic sinus infections. In other words, a gene that was first noticed because of a cloud of dust in a laboratory may play a role in protecting us from disease. The ability to taste bitterness, which probably evolved to warn our ancestors against eating poisonous plants, may have other jobs that are only just beginning to be understood.

Questions 14–18

Classify the following statements as referring to

• A supertasters
• B medium tasters
• C non-tasters

Write the correct letter, A, B or C, next to Questions 14–18.

Questions 19–23

Complete the summary below.

Choose NO MORE THAN TWO WORDS from the passage for each answer.

Counting papillae

Most taste buds are located in the papillae, the tiny bumps that cover the surface of the tongue. Researchers make these visible by painting the front of the tongue with blue 192 words . The papillae stay a 202 words colour, so they can be counted with the help of a magnifying 212 words . Supertasters were found to have more papillae, which seemed to show that they had a larger number of taste 222 words . However, later research has suggested that what happens in the 232 words , or in the receptors, may matter more than the number of papillae.

Questions 24–26

Choose the correct letter, A, B, C or D.

• A She used PTC instead of PROP.
• B She tested people of different ages.
• C She measured how intense the taste was.
• D She studied whether the ability ran in families.

• A It showed that bitter vegetables are harmful to some people.
• B It did not establish that taste caused differences in diet.
• C It found that non-tasters had the poorest diet.
• D It has been repeated with the same results.

• A Sensitivity to one bitter substance does not mean sensitivity to all of them.
• B Most people are sensitive to only a few bitter substances.
• C The number of papillae changes during a person's life.
• D Bitter receptors are found in other parts of the body.

READING PASSAGE 3

You should spend about 20 minutes on Questions 27–40, which are based on Reading Passage 3 below.

Mine is worth more: rethinking the endowment effect

Anyone who has tried to sell a used car, or a house, will probably recognise the feeling. The price that seems fair to us as sellers is often far higher than the price that buyers are willing to pay. We usually put this down to sentiment, or to the buyers' lack of judgement. But that explanation is mistaken. For more than four decades, economists and psychologists have argued that simply owning an object makes us value it more. In 1980, the economist Richard Thaler gave this tendency a name: the endowment effect.

The best-known demonstration of the effect took place in a university classroom in 1990. Thaler and two colleagues, Daniel Kahneman and Jack Knetsch, gave coffee mugs, bearing the university's logo, to half of the students in a class. The other half received nothing. Students with a mug were asked the lowest price at which they would sell it, while those without were asked the highest price they would pay for one. In theory, since the mugs had been handed out at random, the two groups should have valued them roughly equally. In fact, the median price demanded by the owners was around seven dollars, while the median price offered by buyers was less than three. Very few mugs changed hands. A similar experiment by Knetsch, in which students were given either a mug or a bar of chocolate and then offered the chance to swap, produced an equally striking result: about 90 per cent kept whatever they had been given.

The standard explanation for these findings is a principle called loss aversion, which Kahneman had earlier developed with his colleague Amos Tversky. According to this idea, losses weigh more heavily in our minds than gains of the same size; losing fifty dollars, for example, feels considerably worse than finding fifty dollars feels good. Selling a mug means losing it, and so owners demand more to compensate for a loss that buyers, who have nothing to lose, do not feel. The endowment effect quickly became one of the most famous findings in behavioural economics, and it was used to explain a wide range of real-world behaviour, from people's reluctance to change their pension plans to the popularity of free trials, which encourage customers to feel that a product already belongs to them.

I have no wish to deny that the effect is real, or that it can be observed in many situations. Yet I believe that the way it has often been presented, as a fixed feature of human nature, goes too far. Over the past twenty years, a series of studies has suggested that the effect is more fragile, and more dependent on experience and culture, than the early work implied.

The first challenge came from the experiments themselves. In 2005, Charles Plott and Kathryn Zeiler repeated the mug studies, but with a number of changes. Participants were given careful explanations of how the selling and buying procedure worked, they practised with simple examples first, and their decisions were kept anonymous. Under these conditions, the gap between buying and selling prices disappeared. Plott and Zeiler argued that what had looked like a basic feature of human preferences might partly be a result of how participants understood the task. Their conclusions have themselves been disputed, and other researchers have since found the effect under similar conditions. But the debate showed that the size of the effect can depend heavily on the way an experiment is designed.

A second line of research looked at people with different levels of trading experience. The economist John List studied traders at sports memorabilia fairs in the United States, and found that those who bought and sold regularly showed little or no endowment effect, while inexperienced traders showed a strong one. Experience, it seemed, taught people to see objects as goods to be exchanged, rather than as possessions.

The most striking evidence, in my view, comes from a study published in 2014. A team led by Coren Apicella worked with the Hadza, a group of hunter-gatherers in northern Tanzania. Some Hadza live in remote areas and have very little contact with markets or money. Others live near villages that receive tourists, and they regularly sell goods to visitors. The researchers gave participants one of two items of similar value, such as packets of biscuits in two different flavours, and offered them the chance to swap. Among the Hadza with little market contact, people were just as likely to swap as to keep what they had: there was no endowment effect. Among those with more exposure to markets, however, the effect appeared. If this finding is correct, then the endowment effect may not be a universal law of human behaviour at all, but something that develops in societies built around buying and selling.

Why does this matter? Partly because the endowment effect has been used to justify a particular view of human beings as consistently irrational, and of their choices as easily predictable by those who design products and policies. If the effect is weaker than once thought, or varies widely between groups, then policies based on it may not work as intended. A government that sets a pension plan as the automatic option, on the assumption that people will be reluctant to give up what they have been given, may find that some groups behave quite differently.

None of this means that businesses are wrong to offer free trials, or that we should stop being suspicious of our own pricing when we sell a car. The feeling that our possessions are special is familiar to most of us, and it is not likely to disappear. But it is worth remembering that the most famous experiments in this field were carried out mainly with university students in wealthy countries, people who have spent their whole lives surrounded by markets. Before we describe a pattern of behaviour as part of human nature, we should be sure that we have looked far enough beyond our own classrooms.

Questions 27–30

Choose the correct letter, A, B, C or D.

• A usually set prices that are too low.
• B often explain high prices in the wrong way.
• C are more emotional than buyers.
• D are better judges of value than buyers.

• A Owners and buyers valued the mugs about equally.
• B Buyers were willing to pay around seven dollars.
• C Most of the mugs were sold.
• D Owners asked for more than twice what buyers offered.

• A why people rarely buy goods they have tried for free.
• B why people tend not to change their pension plans.
• C why prices for used cars have risen.
• D why people prefer chocolate to mugs.

• A They have been accepted by most researchers.
• B They were based on too few participants.
• C Not everyone agrees with them.
• D They proved that the endowment effect does not exist.

Questions 31–35

Complete the summary below.

Choose ONE WORD ONLY from the passage for each answer.

Studies that challenged the endowment effect

When Plott and Zeiler repeated the mug studies, participants received detailed explanations of the procedure, 311 word with simple examples first, and made their decisions anonymously. As a result, the difference between buying and selling prices disappeared. John List found that people who traded regularly at sports memorabilia 321 word showed little or no endowment effect. In Tanzania, Apicella's team offered Hadza participants items such as 331 word in different flavours. Those living in remote areas showed no endowment effect, but those who often sold goods to 341 word did. This suggests that the effect may develop through regular exposure to 351 word .

Questions 36–40

Do the following statements agree with the claims of the writer in Reading Passage 3?

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