Reading Test 6

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

A vault at the end of the world

On the Norwegian island of Spitsbergen, around 1,300 kilometres from the North Pole, a narrow concrete entrance projects from the side of a mountain. Behind it, a tunnel leads more than 100 metres into the rock to three chambers, where well over a million packets of seeds are stored in sealed boxes on metal shelves. This is the Svalbard Global Seed Vault, which opened in 2008 with the aim of protecting the world's crop diversity against disaster.

The vault does not hold seeds of its own. Instead, it acts as a backup for the roughly 1,700 seed banks, or genebanks, that exist around the world, most of them run by governments or research institutions. These genebanks store samples of the many thousands of varieties of crops that farmers have developed over the past 10,000 years, including traditional varieties that are no longer widely grown. Such varieties may contain genes that help plants to resist disease, drought or heat, and plant breeders use them to develop new crops. Yet genebanks themselves are vulnerable. Some have been destroyed by war or natural disasters, while others have lost samples because of power cuts, poor management or a lack of funding.

Depositing seeds in the vault works rather like renting a safe deposit box in a bank. The organisations that send seeds remain their owners, and only they can withdraw them; the boxes are never opened by the vault's staff. Storage is free of charge, with the costs of running the facility shared between the Norwegian government and an international organisation that supports crop diversity.

The location was chosen with great care. Svalbard is remote, geologically stable and far above sea level, so that the vault would remain dry even if the polar ice melted completely. The seeds are kept at minus 18 degrees Celsius, a temperature at which many types of seed can survive for decades or even centuries. This temperature is maintained by electric cooling, but the surrounding rock is permanently frozen, so that if the power were to fail, the chambers would warm only slowly, and never above freezing.

The vault received its first request for a withdrawal in 2015. An international agricultural research centre that had been based in the Syrian city of Aleppo had been forced to move because of the war, and could no longer use its genebank there. It asked for the return of the samples it had deposited in Svalbard, and used them to grow new seeds at its new sites in Lebanon and Morocco. Some of these were later sent back to the vault, so that the backup was restored.

The vault has not been entirely free of problems. In 2017, following unusually high temperatures in the Arctic, melting snow caused water to enter the entrance tunnel. The seeds themselves were never at risk, as the water did not reach the storage chambers, but the incident raised concerns about the effects of climate change on the region. The Norwegian government responded by carrying out extensive improvements, including building a new, waterproof access tunnel.

Some critics argue that, by focusing on storing seeds in a frozen vault, the world risks neglecting another important form of conservation: the continued growing of traditional varieties by farmers in their fields. Crops that are grown year after year continue to adapt to local conditions, including changes in climate and new diseases, while frozen seeds remain as they were when they were collected. Supporters of the vault agree that both forms of conservation are needed, and point out that it was never intended to replace the work of farmers or of genebanks, but only to provide a last line of defence.

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

Why teenagers should sleep in

A Most parents of teenagers will recognise the pattern: children who once woke early and fell asleep without difficulty begin, around the age of thirteen or fourteen, to stay up late and to struggle to get out of bed in the morning. For many years, this was blamed on laziness, or on the attractions of television and, later, of smartphones. Research over the past few decades, however, has shown that the main cause is biological.

B The timing of sleep is controlled partly by the body's internal clock, which regulates the release of melatonin, a hormone that makes us feel sleepy. During adolescence, the release of melatonin in the evening begins later, so that teenagers naturally feel sleepy at around 11 pm or later, compared with perhaps 9 pm for younger children. At the same time, they still need between eight and ten hours of sleep a night. A teenager who falls asleep at 11 pm but must get up at 6.30 am to get to school is therefore likely to be short of sleep, and over the course of a week, the shortage can become considerable. Many try to make up for it at the weekend by sleeping until late morning, but this only shifts their internal clock even later, making it harder still to fall asleep early on Sunday night. Sleep researchers sometimes compare the effect to the jet lag experienced by travellers who fly across several time zones, except that for many teenagers it is repeated every week.

C The effects of lack of sleep are well documented. Tired students find it harder to concentrate and to remember what they have learned, and their academic performance suffers. Sleep loss is also associated with low mood, anxiety and depression, and with poorer physical health. Perhaps most worryingly, it increases the risk of accidents: studies have found that young drivers who are short of sleep are significantly more likely to be involved in car crashes.

D These findings have led to calls for schools to start later in the day. In 2014, the American Academy of Pediatrics recommended that secondary schools should not begin before 8.30 am, at a time when many American high schools started before 8 am. In 2019, California became the first US state to pass a law requiring most high schools to start no earlier than 8.30, and several other states have since followed. A number of individual school districts had already made the change, and similar debates have taken place in other countries, including the United Kingdom, where a few schools have experimented with starting lessons at 10 am for older students. Supporters of later start times stress that the aim is not to give teenagers more free time, but to match the school day more closely to their natural pattern of sleep.

E One of the most carefully studied cases is that of Seattle, where, in 2016, the start time of secondary schools was moved from 7.50 am to 8.45 am. Researchers measured the sleep of students before and after the change using wrist monitors, rather than relying on the students' own reports. They found that students slept on average 34 minutes longer each night after the change, and that they did not simply go to bed later. The students' grades in the subject studied improved, and they were less likely to be late or absent, particularly in schools in poorer areas.

F Despite such evidence, changing school times is often difficult. Later start times mean later finishing times, which may leave less time for sports, part-time jobs and other activities after school. Bus timetables may need to be reorganised, and some parents find it harder to combine a later start with their own working hours. Younger children may be affected too, as some districts have dealt with the problem of running buses by making primary schools start earlier, even though young children are naturally more alert in the morning anyway. For these reasons, proposals for later start times have often met strong local opposition, and some have been abandoned. Researchers argue that these difficulties, while real, should be weighed against the costs of tiredness, which are less visible but affect students every day. They also point out that later start times are not a complete solution: teenagers who use screens late into the night, or who drink caffeinated drinks in the evening, may still find it hard to get enough sleep, however late the school day begins.

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

The power of belief

In 1955, an American doctor named Henry Beecher published a paper entitled 'The Powerful Placebo'. Reviewing fifteen studies, he concluded that around a third of patients experienced a significant improvement in their symptoms after receiving a placebo, a treatment with no active ingredient, such as a sugar pill or an injection of salt water. The paper had a lasting influence. It helped to establish the randomised controlled trial, in which a new drug is compared with a placebo, as the standard method of testing medical treatments, and it encouraged the belief that the mind has an extraordinary power to heal the body.

Later researchers, however, found serious problems with Beecher's analysis. Many patients get better without any treatment at all, because many illnesses improve naturally over time, or because symptoms that are unusually severe when a patient first seeks help are likely to be less severe later. Beecher had not distinguished between these effects and the effect of the placebo itself. In 2001, two Danish researchers, Asbjørn Hróbjartsson and Peter Gøtzsche, examined 130 trials in which patients given a placebo had been compared with patients who received no treatment at all. They found little evidence that placebos had powerful effects on objective outcomes, such as blood pressure or the size of a tumour. The main exception was pain, together with other symptoms that patients report themselves, where placebos did seem to produce a modest benefit.

That benefit, though, is real. Brain-imaging studies have shown that when people expect a treatment to relieve pain, their brains release natural painkilling chemicals, and activity in areas associated with the experience of pain is reduced. The effect is shaped by expectations in surprising ways. Two placebo pills appear to work better than one, and injections better than pills. In one experiment, the economist Dan Ariely and his colleagues gave volunteers mild electric shocks before and after they took a placebo pill. Volunteers who were told that the pill cost $2.50 reported greater pain relief than those who were told that it had been reduced in price to just ten cents.

The opposite of the placebo effect, known as the nocebo effect, can be equally powerful. Patients who are warned about the possible side effects of a drug are more likely to report experiencing them, even when they have actually been given a placebo. In trials of cholesterol-lowering drugs called statins, many patients report muscle pain; yet in carefully designed studies in which patients did not know whether they were taking a statin or a placebo, the pain was reported almost as often with the placebo. This has led some doctors to argue that the way information about side effects is communicated to patients should be reconsidered.

The use of placebos in ordinary medical practice raises difficult ethical questions. If a placebo can relieve pain, should doctors prescribe one? Doing so would seem to require deceiving the patient, which most medical ethicists regard as unacceptable. Remarkably, however, there is evidence that deception may not be necessary. In 2010, a team led by Ted Kaptchuk of Harvard Medical School gave patients with irritable bowel syndrome pills that they were told openly were placebos, 'like sugar pills', which had been shown to produce improvement through mind-body processes. After three weeks, these patients reported significantly greater improvement than a group who received no treatment. Similar 'open-label' placebo studies have since been carried out for conditions including back pain and fatigue, with encouraging results.

How can a treatment work when patients know it is fake? Kaptchuk has suggested that the ritual of treatment itself may be important: the attention of a caring doctor, the act of taking a pill at regular times, and the hope of getting better. If he is right, part of what makes medicine effective may have less to do with chemistry than with the relationship between patient and doctor. This does not mean that placebos can replace effective drugs, or that positive thinking can cure serious illness, claims which are not supported by evidence. But it does suggest that doctors should pay as much attention to how they treat their patients as to what they prescribe.