IELTS Academic Reading practice test 1 (with answers)

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

Farming Upwards

Can stacking crops indoors help feed the world’s growing cities?

For most of human history, farming has been a horizontal activity. Crops have spread outwards across fields, and when more food has been needed, more land has been cleared. Today, however, around 40 per cent of the planet’s ice-free land is already used for agriculture, and the United Nations expects the world’s urban population to rise by more than two billion people by 2050. This combination has led a growing number of engineers and growers to ask whether food could be produced not across the landscape, but upwards, in multi-storey buildings close to the people who eat it.

The idea of the ‘vertical farm’ is usually credited to Dickson Despommier, a professor of public health at Columbia University in New York. In 1999 he set his students the task of designing a rooftop garden that could feed the population of Manhattan. When their calculations showed that rooftops could supply only around two per cent of the island’s needs, Despommier suggested that they think instead of entire buildings devoted to growing food. The concept was initially dismissed by many agricultural scientists as impractical, but it attracted considerable attention from architects, and within a decade the first commercial facilities had opened in Japan, Singapore and the United States.

Modern vertical farms rarely use soil. Most rely on hydroponics, in which plant roots are suspended in a solution of water and dissolved minerals, or on aeroponics, where the roots hang in the air and are sprayed with a nutrient mist at regular intervals. Because the water is collected and recirculated, these systems typically use 90 to 95 per cent less water than conventional field agriculture. Light is provided by light-emitting diodes (LEDs), which can be tuned to the particular wavelengths – mainly red and blue – that plants use most efficiently for photosynthesis. Temperature, humidity and carbon dioxide levels are all controlled by computer, so that conditions remain the same whatever the weather outside.

Supporters point to a number of advantages. Since the crops are grown in a sealed environment, pests are largely excluded and pesticides are seldom required. Harvests are no longer seasonal: a lettuce farm in Kyoto, for example, claims to produce up to twenty crops a year, compared with two or three in an open field. Growing food in or near cities also shortens supply chains. Fresh produce in many countries travels more than a thousand kilometres before it reaches a supermarket shelf, losing flavour and nutritional value along the way; a vertical farm can deliver salad to a restaurant within hours of it being picked.

The most serious obstacle is energy. Sunlight is free, whereas electric lighting is not, and lighting alone can account for up to half of a vertical farm’s running costs. One study at Cornell University estimated that producing a kilogram of lettuce indoors required around 250 kilowatt-hours of electricity – far more than greenhouse cultivation. If that electricity comes from burning fossil fuels, the environmental benefits of saving land and water may be cancelled out by higher carbon emissions. For this reason, several newer projects have been located next to wind farms or have installed solar panels, although these rarely meet more than a fraction of the farm’s total demand.

Cost also limits the range of crops that can be grown profitably. Leafy greens such as lettuce, spinach and basil are ideal: they grow quickly, are light, and command high prices, and almost all of the plant can be sold. Staple crops are a different matter. Wheat, rice and maize take months to mature and occupy a great deal of space for relatively little value per kilogram. Researchers at Utah State University calculated that wheat grown indoors under LEDs would cost several times more than imported grain, even though yields per square metre were impressive. For the foreseeable future, therefore, vertical farms are unlikely to replace the vast fields that provide most of the world’s calories.

Despite these limitations, the industry has continued to attract investment, and some experts believe its greatest contribution may be indirect. The precise control of light and nutrients that vertical farms require has generated large amounts of data about how plants respond to their environment, and this knowledge is now being applied in ordinary greenhouses. Others see the technology as a form of insurance. In regions with little fertile land or reliable rainfall, such as parts of the Middle East, or in places where supply chains are easily disrupted, the ability to grow fresh food locally all year round may be worth the extra expense. Farming upwards, it seems, will not replace farming outwards, but it may well find a permanent place alongside it.

Questions 1–6

Do the following statements agree with the information given in Reading Passage 1?

In boxes 1–6 on your answer sheet, write

TRUE if the statement agrees with the information

FALSE if the statement contradicts the information

NOT GIVEN if there is no information on this

1  The majority of the Earth’s ice-free land is currently used for farming.

2  Despommier’s students found that rooftop gardens could provide only a small part of Manhattan’s food needs.

3  Agricultural scientists were quick to support the concept of vertical farming.

4  Aeroponic systems use less water than hydroponic systems.

5  The LEDs used in vertical farms can be adjusted to suit the needs of plants.

6  The Kyoto lettuce farm sells most of its produce to restaurants.

Questions 7–13

Complete the notes below.

Choose ONE WORD ONLY from the passage for each answer.

Write your answers in boxes 7–13 on your answer sheet.

Vertical farming: benefits and problems

Benefits

• there is little need for (7) ________ because insects are kept out

• crops are not limited by the (8) ________

• shorter supply chains mean food keeps its taste and its (9) ________ value

Problems

• high consumption of (10) ________, mostly for lighting

• possible increase in carbon (11) ________ if fossil fuels are used

• crops such as wheat and rice need a lot of (12) ________ and take months to grow

Future role

• research data is now being used in conventional (13) ________

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

The Hidden Conversations of Elephants

A  For decades, visitors to the national parks of East Africa have watched elephant herds move across the plains in apparently silent coordination. A group feeding in one valley will suddenly stop, lift their heads and begin walking in the same direction as another group several kilometres away, without any sound audible to human ears. Early naturalists put this down to a mysterious ‘sixth sense’. It was not until the 1980s that scientists discovered that much of the communication between elephants takes place at frequencies too low for people to hear.

B  The breakthrough came in 1984, when the American biologist Katy Payne was observing Asian elephants at a zoo in Oregon. Standing beside their enclosure, she noticed a faint throbbing in the air, similar to the sensation she remembered from standing next to a church organ as a child. Suspecting that the animals were producing sounds below the range of human hearing, she returned with recording equipment that could capture infrasound – sound waves with a frequency below 20 hertz. When the recordings were played back at higher speed, they revealed a rich variety of rumbling calls.

C  Infrasound has an important advantage for animals that live in large, widely scattered groups: it travels much further than higher-pitched sound, because long waves are less easily absorbed by vegetation and the ground. Under ideal conditions – typically on cool, still evenings, when a layer of cold air close to the ground traps sound – an elephant rumble may be detected by other elephants up to ten kilometres away. During the heat of the day, by contrast, the range may fall to less than a quarter of that distance. Researchers have found that elephants appear to time much of their long-distance calling to the early evening, as if they were aware of the difference.

D  Not all of the messages are carried through the air. Caitlin O’Connell-Rodwell, working in Namibia, observed that elephants at a waterhole would sometimes freeze, lean forward and press their feet firmly into the ground. She suspected that they were ‘listening’ to vibrations travelling through the earth itself. Her experiments, in which recorded alarm calls were transmitted through the soil using buried speakers, showed that elephants did respond to seismic signals, often becoming alert and moving closer together. The animals’ feet and trunks contain specialised nerve endings which are highly sensitive to such vibrations.

E  The content of elephant calls is now known to be surprisingly specific. Joyce Poole, who has studied the elephants of Amboseli in Kenya for more than forty years, has catalogued over seventy distinct vocal and gestural signals. Some are used to coordinate the movement of a family group, others to greet relatives after a separation or to warn of danger. Remarkably, field experiments have shown that elephants can distinguish between the voices of individuals. When the recorded call of a family member is played, a herd will often answer and approach the speaker; the call of an unfamiliar elephant, on the other hand, may cause the group to bunch together defensively.

F  Poole’s team has also shown that elephants respond differently to different human threats. In one study, the recorded voices of men from the Maasai community, who have historically come into conflict with elephants over grazing land, caused herds to retreat quickly, while the voices of men from another local group with no such history produced a much milder reaction. Even more strikingly, a separate study found that the animals reacted less strongly to the voices of Maasai women and children, suggesting that elephants assess not only who is speaking but how dangerous that person is likely to be.

G  Such discoveries have practical value. In parts of Africa and Asia, the expansion of farmland has brought elephants into regular contact with people, and crop-raiding by elephants can destroy a family’s harvest in a single night. Understanding how elephants communicate is helping conservationists to develop early-warning systems that detect approaching herds by their rumbles, as well as deterrents that play recorded warning calls to discourage elephants from entering fields. While such methods are not a complete solution, they offer the hope of reducing conflict without harming the animals themselves.

Questions 14–19

Reading Passage 2 has seven paragraphs, A–G.

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

Write the correct number, i–ix, in boxes 14–19 on your answer sheet.

List of Headings

i  Why some sounds travel further than others

ii  Recognising who is calling

iii  A puzzling behaviour finally explained

iv  An accidental discovery during a visit

v  Using research to protect people and animals

vi  The difficulty of recording elephants in the wild

vii  Messages sent through the ground

viii  Judging the level of risk from humans

ix  How elephants learn their calls from their mothers

Example: Paragraph A — iii

14  Paragraph B

15  Paragraph C

16  Paragraph D

17  Paragraph E

18  Paragraph F

19  Paragraph G

Questions 20–23

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

Write the correct letter in boxes 20–23 on your answer sheet.

20  What first made Katy Payne think that the elephants were producing sounds?

A  She saw the elephants reacting to something she could not hear.

B  She felt a physical sensation in the air near them.

C  She heard faint rumbling sounds from the enclosure.

D  She was told about it by the zoo’s keepers.

21  According to paragraph C, elephant calls travel furthest

A  in the middle of the day.

B  when there is a strong wind.

C  on calm, cool evenings.

D  in areas with thick vegetation.

22  In O’Connell-Rodwell’s experiments, the elephants

A  ignored signals that came through the soil.

B  moved away from the buried speakers.

C  became more alert and gathered together.

D  answered the signals with calls of their own.

23  What happened when elephants heard the call of an unfamiliar elephant?

A  They approached the speaker.

B  They formed a tight, protective group.

C  They called back immediately.

D  They showed no reaction at all.

Questions 24–26

Look at the following findings (Questions 24–26) and the list of researchers below.

Match each finding with the correct researcher, A, B or C.

Write the correct letter, A, B or C, in boxes 24–26 on your answer sheet.

List of Researchers

A  Katy Payne

B  Caitlin O’Connell-Rodwell

C  Joyce Poole

24  Elephants use more than seventy different signals.

25  Elephants can detect vibrations through their feet.

26  Playing recordings faster makes elephant calls audible to humans.

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

In Defence of Forgetting

Forgetting has a poor reputation. We treat it as a failure – the name that will not come, the appointment that slips past, the facts learned for an examination that vanish within weeks. Popular books promise to ‘boost’ memory as though it were a muscle that weakens through neglect, and a large industry sells puzzles and applications claiming to keep it in shape. Yet a growing body of research suggests that this view is mistaken. Forgetting, many psychologists now argue, is not simply the breakdown of a system designed to store everything; it is an essential feature of a mind that has to cope with a changing world.

The scientific study of forgetting began in the 1880s with the German psychologist Hermann Ebbinghaus, who spent years memorising lists of meaningless syllables and testing himself at intervals. His results produced the famous ‘forgetting curve’, which showed that most of what is learned is lost within the first day, after which the rate of loss gradually slows. For much of the following century, researchers assumed that forgetting was largely passive: memories, like footprints in sand, simply faded with time. This ‘decay’ theory was intuitively appealing, but it proved remarkably difficult to test, since it is almost impossible to stop a person from experiencing anything at all between learning and recall.

An alternative explanation, known as interference theory, gained support from experiments in the 1950s and 1960s. These showed that people forget far more when they learn similar material in between, suggesting that memories are not so much worn away as crowded out by competing ones. A driver who has parked in a different space at the same car park every day for a year will have little difficulty remembering where the car is today, but will struggle to recall where it was last Tuesday. In this view, the problem is not that the information has disappeared but that it has become hard to locate among many similar memories.

More recently, neuroscientists have discovered that the brain also forgets actively. Studies of fruit flies and mice have identified chemical processes that steadily weaken the connections between nerve cells, and these processes appear to be switched on, rather than merely allowed to happen. When researchers blocked them in mice, the animals remembered more – but they also became worse at adapting to new situations. Mice trained to find a hidden platform in a pool, for example, continued searching in the old location long after the platform had been moved. Their superior memory had become a handicap.

This finding supports the view, put forward by the Canadian researchers Blake Richards and Paul Frankland, that the purpose of memory is not to preserve the past accurately but to help us make good decisions in the future. A mind that recorded every detail would, they suggest, be overwhelmed by irrelevant information and would find it hard to generalise from experience. By discarding specific details while keeping the overall pattern, the brain is able to recognise that a new situation resembles an old one even when the circumstances are not exactly the same. In other words, a degree of forgetting allows us to see the wood rather than the trees.

Rare individuals who struggle to forget seem to confirm this. People with a condition known as highly superior autobiographical memory can recall what they did on almost any day of their adult lives, often down to the weather and what they ate. Far from regarding this as a gift, several have described it as exhausting, and studies have found that they are no better than average at ordinary memory tasks such as recalling a list of words. Their extraordinary recall of personal events does not, apparently, translate into a general advantage.

None of this means that all forgetting is beneficial. Conditions such as dementia, in which memory loss is severe and progressive, cause real suffering, and the inability to retain new information can make independent life impossible. Nor does it mean that students should welcome the loss of material they need for an examination. But it does suggest that the common anxiety about everyday forgetfulness may be misplaced. Occasionally failing to recall a colleague’s name is not necessarily a sign of decline; it may simply be evidence of a brain doing what it was designed to do – clearing space, so that what matters can be found.

Questions 27–31

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

In boxes 27–31 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

27  The idea that memory can be strengthened like a muscle is widely accepted by the public.

28  Memory-training applications have been proven to prevent forgetting.

29  Ebbinghaus found that forgetting happens at a steady rate over time.

30  The decay theory of forgetting was easy to prove in laboratory conditions.

31  Worry about occasional everyday forgetfulness is often unnecessary.

Questions 32–36

Complete the summary using the list of words, A–I, below.

Write the correct letter, A–I, in boxes 32–36 on your answer sheet.

Active forgetting in animals

Research on flies and mice has revealed (32) ________ processes that weaken links between nerve cells. These processes are deliberately (33) ________ rather than happening by chance. When scientists prevented them, mice had better memories but were less able to (34) ________ to change. For instance, they kept looking for a platform in its (35) ________ position. According to Richards and Frankland, memory exists mainly to help us make good (36) ________.

Questions 37–40

Complete each sentence with the correct ending, A–F, below.

Write the correct letter, A–F, in boxes 37–40 on your answer sheet.

Sentence endings

A  because similar memories compete with each other.

B  because the information has been completely erased.

C  is not reflected in better performance on standard tests.

D  makes it easier to recognise patterns in new situations.

E  was first measured by testing with meaningless syllables.

F  can be prevented by regular mental exercise.

37  The way in which memories are lost over time

38  According to interference theory, people forget

39  Losing specific details while keeping the general picture

40  The exceptional personal memory of some individuals