IELTS Academic Reading Practice Test 481

The Karakoram Highway is frequently described as the highest paved international road in the world. It runs for roughly 1,300 kilometres, from Hasan Abdal in northern Pakistan to Kashgar in the far west of China, crossing the Karakoram range by way of the Khunjerab Pass at about 4,700 metres above sea level. Roughly two-thirds of the road lies in Pakistan. For much of its length it follows the valleys of the Indus and Hunza rivers, squeezing between cliffs and the water, and near the town of Jaglot it passes the point where the Karakoram, Himalaya and Hindu Kush ranges meet.

Long before any road existed, this corridor formed part of the network of trade routes later known as the Silk Road. Caravans carried goods between the plains of the Indian subcontinent and the oases of Central Asia, and the valleys that now carry the highway were a link in that chain. Between them, however, there was only a narrow track along which people travelled on foot or with pack animals. A journey that today takes an hour might then take a day, and in winter the track was frequently impassable. Villages grew most of what they needed and had little access to anything produced elsewhere.

Construction began in 1959 as a joint undertaking by the governments of Pakistan and China. The work was carried out largely by the Frontier Works Organisation, the construction arm of the Pakistani army, with assistance from Chinese engineers and equipment. It took twenty years. Much of the route had to be cut into near-vertical rock. In places there was no room for heavy machinery, so men were lowered on ropes to drill the holes into which explosives were packed, and the shattered stone was tipped straight into the river below. For years the surface was little more than compacted rubble, and a single rainstorm could close it.

The conditions were as hostile as the terrain. Much of the road lies above 3,000 metres, where the air holds very little oxygen and the weather can change within minutes. The working season was short, because the high passes were buried under snow for months at a time. Completed sections were repeatedly destroyed by landslides and floods and had to be rebuilt, sometimes more than once.

Chinese and Pakistani workers lived in camps at altitudes where even sleeping was difficult. Every kilometre of finished road had to be maintained by hand, and a stretch completed one summer could be lost the next. Hundreds of labourers are believed to have died, although no comprehensive record was kept, and the true figure may never be established.

The road remains fragile. The mountains it crosses are young and geologically active, and every spring the slopes above the carriageway release rock and mud. The most dramatic interruption came in January 2010, when a huge landslide in the Hunza valley blocked the river and created a lake that eventually submerged some twenty kilometres of the highway. For five years traffic had to be carried across the water on boats, with passengers and goods transferred from one lorry to another on either shore, until a series of tunnels and a new stretch of road opened in 2015.

For the people of the valleys the consequences have been profound. Families that had once grown apricots and other crops only for their own use could now sell them in the towns, and a journey to a hospital that had taken a whole day could be completed in an hour. Secondary schooling became possible for children whose villages had never had a teacher. Tourism expanded: trekkers and mountaineers came for peaks such as Rakaposhi, and guesthouses opened in villages that had previously had none. Young people left for the cities in larger numbers, and money sent home became an important source of income.

The changes have not come without costs. Villages that were once almost self-sufficient now depend on supplies brought in by lorry, and a landslide far up the valley can empty the shops within days. Traffic has increased steadily, and the dust it raises settles on orchards and roofs. Whether the benefits of the highway outweigh these costs is a matter of argument among those who live beside it, and the argument is unlikely to be settled soon.

In the twenty-first century the highway acquired a new importance as part of the China–Pakistan Economic Corridor, a programme of infrastructure intended to link Kashgar with the Pakistani port of Gwadar on the Arabian Sea. Sections have been widened and straightened, and some of the most dangerous stretches replaced by tunnels. Lorries now carry Chinese machinery and manufactured goods southwards, and Pakistani fruit and textiles northwards, although the volume of trade has grown more slowly than the planners hoped.

At its northern end the road crosses Khunjerab National Park, created in 1975 to protect the Marco Polo sheep and the snow leopard. The park's high pastures are grazed in summer by herds brought up from the valleys below. The pass itself is normally closed by snow from late November until April, when the border posts on either side stand empty and the road becomes a corridor of packed ice. For the rest of the year, however, it remains the only land link between the villages of the Hunza valley and the rest of Pakistan.

Most people assume that counting is a skill that separates human beings from the rest of the animal world, and that it depends on the language of numbers. Neither assumption is safe. A growing body of experiments shows that creatures with very small brains can compare quantities, and that the ability appears in animals that have never been taught a symbol for a number. What remains in dispute is whether they are genuinely counting, in the sense that a child counts, or merely estimating. Either way, the mental machinery involved is far older than arithmetic.

Psychologists distinguish two systems. One, often called the approximate number system, allows rapid judgements about large quantities without any counting: a glance at a flock tells you whether it is bigger than the one beside it. This system obeys a rule of proportion. Discrimination is easy when the quantities differ by a factor of two, such as eight against sixteen, and difficult when they differ by a small fraction, such as eight against ten. The second system is exact but limited: it tracks individual objects, and in human beings it holds only about three or four at once. Many animals appear to possess both.

Fish provide some of the cleanest evidence for the approximate system. A small freshwater fish such as the mosquitofish prefers to join the larger of two shoals, which is presumed to reduce its chance of being eaten. In laboratory experiments, mosquitofish chose the larger group when the difference was large but failed when two shoals differed by only one fish in four or five. Comparable limits have been found in many other species, and the pattern is strikingly consistent: the greater the ratio between the quantities, the easier the discrimination. The fish, in other words, is not counting; it is weighing up a rough difference that becomes clearer as the difference widens.

Insects are more capable than their nervous systems might suggest. Honeybees can be trained to fly past a set number of landmarks before entering a chamber where sugar water is waiting, and they learn to stop at the correct one. They can also be taught to choose the smaller of two sets of objects, and some experiments indicate that they treat an empty set as a quantity of its own rather than as nothing at all. Whether this amounts to an understanding of zero is fiercely debated, but the bees are clearly doing something more than responding to the total area of what they see.

Some insects use number-like information in a different way. A desert ant leaving its nest counts its own steps, so that an individual that has walked a hundred paces outwards knows to walk roughly a hundred paces back. Nothing is being counted except movement, yet the result is a numerical estimate of position. Examples of this kind are a reminder that behaviour which looks like arithmetic can arise from mechanisms that have nothing to do with number.

Among birds, the most celebrated case is a grey parrot trained in the United States by a psychologist who spent decades working with a single individual. The bird could answer spoken questions about the number of objects in a tray, and it was reliably correct with sets of up to six, whether the objects were keys, balls of wool or pieces of wood. Newly hatched chicks have also been shown to prefer the larger of two groups, suggesting that at least a rudimentary sense of quantity needs no experience at all.

Primates have gone further. In Japan, researchers taught a chimpanzee to associate the numerals 1 to 9 with sets of objects, and the animal could later touch the numeral that matched a set it had been shown. Monkeys have been trained to compare arrays of dots and to select the larger, and their accuracy falls in exactly the way the approximate system predicts as the difference between the arrays narrows. Such results blur the line between number words and number sense, though the chimpanzees needed years of training to acquire what a child of five learns in a few months.

Designing these experiments is harder than it sounds. A famous cautionary example is a horse called Clever Hans, which appeared at the beginning of the twentieth century to solve arithmetic problems by tapping its hoof. Careful investigation showed that the horse was responding to tiny, unconscious movements in the person questioning it. Modern researchers therefore try to ensure that animals cannot use other features of the display. If the larger set also covers more area, or if its items are larger, packed at a greater density or left on the screen for longer, an animal can succeed without counting at all. Experiments therefore present different numbers of objects of the same size and total area.

What all this means is still uncertain. Most researchers accept that many species represent number, in the sense that they are sensitive to quantity, but whether any of them possesses a genuine concept of number — something that can be manipulated and applied to new situations — is unresolved. Nor is it clear what such abilities are for in the wild. A fish that joins the larger shoal, or a bee that returns to the richer patch of flowers, may simply be using a rough sense of more and less, which is useful enough.

On 12 October 2019, in a park in Vienna, Eliud Kipchoge ran a marathon in one hour, fifty-nine minutes and forty seconds, the first person to cover the distance in under two hours. The attempt had been carefully staged: a rotating team of pacemakers sheltered him from the wind, drinks were handed up by cyclists, and no other competitors took part. For these reasons the time is not recognised as a world record. What fascinated engineers quite as much as athletes was what he was wearing: a prototype shoe with a sole almost four centimetres thick and a stiff plate hidden inside it.

The advantage comes from two components. The midsole is made of a lightweight foam that is much thicker than in earlier racing shoes and returns more energy than traditional foam rubber. Inside it lies a curved plate of carbon fibre, which stiffens the sole and, according to sports engineers, works rather like a spring: it stores energy as the foot lands and gives it back as the runner pushes off. The combination reduces the energy cost of running at a given speed. Independent laboratory tests have measured improvements in running economy of around four per cent, which over a marathon is worth several minutes.

New footwear is as old as organised sport. The synthetic foam midsole, which transformed running in the 1970s, was itself a technological leap, and the waffle-patterned rubber sole devised by the coach Bill Bowerman in the early 1970s was quickly copied. Spikes, gel cushions and air pockets followed. Every era has had its technological advance, and each was denounced in its turn, usually by those who had competed before it arrived. On the whole, athletics has absorbed these changes by allowing them and then revising the rules when something seemed to go too far.

Critics of the new shoes make three arguments. The first is that the athlete has become less important than the equipment, so that races are decided in a laboratory rather than on the road. The second is that the shoes are expensive and not everyone can obtain them, which distorts competition. The third concerns records. On the question of records, the critics have a point: a marathon time set in 1990 and one set today cannot be compared as though nothing had changed, and the lists of best performances now mix two different eras.

Defenders of the shoes reply that the improvement is modest and that the alternative — standardised shoes issued to everyone — would be unenforceable and undesirable. Four per cent is significant in a marathon, but it does not turn a club runner into an international; the winners of major races are still the men and women with the best combination of physiology, training and tactical judgement. Nor, they say, do the shoes alter tactics: the pace still has to be judged, and the last kilometres still hurt. On this view the shoes are a refinement, not a revolution, and the fuss is out of proportion to the effect.

Swimming offers the clearest precedent, because the sport faced a similar question only a decade ago. In the late 2000s a generation of swimsuits made from polyurethane and similar materials compressed the body and trapped air, and more than forty world records were set at the 2009 world championships in Rome. The governing body, after initially approving the suits, reversed its position and banned them from competitive use in 2010. Manufacturers protested that they had followed the rules as they were then written, which was true. Performances fell back immediately, and the sport spent years arguing about whether the decision had been right.

Athletics chose a different course. In January 2020 the governing body, World Athletics, announced rules for road racing shoes: the sole may be no more than forty millimetres thick, it may contain no more than one rigid plate, and any shoe used in competition must have been on sale to the public for four months. A ban, in my view, would have been a mistake, but some limit was clearly needed, and this is the kind of limit that can be adjusted as shoes develop. Enforcement will not be easy, since officials cannot cut open a shoe on the start line, and much will depend on manufacturers declaring what they have produced.

The question of price troubles me more than the question of records. A top-of-the-range racing shoe now costs several times what a decent training shoe did a generation ago, and the athletes who benefit most are those whose sponsors supply the shoes for nothing. For the ordinary runner paying for a place in a city marathon, the promise of four per cent is a powerful sales message, and the expense falls on people for whom it is a real sum of money. That is a question of access rather than of sporting ethics, but it is the one most likely to shape who takes part.

My conclusion is therefore an unfashionable one, and it will please neither side. The shoes should be regulated, not prohibited; the rules should be reviewed every few years; and the results should be read with a little scepticism. I have seen no evidence that they transform an ordinary club runner into a champion, and the decisive factor remains the runner. Technology has never been absent from sport, and attempts to keep it out have usually failed.