IELTS Academic Reading Test 9 with Answers

You should spend about 20 minutes on Questions 1–13.

The living fossil of the shoreline

On certain nights in late spring, along the muddy shores of the eastern coast of North America, the sea delivers up an extraordinary sight. Thousands upon thousands of horseshoe crabs crawl out of the water together to lay their eggs on the beach, their smooth, domed shells glinting in the moonlight. The scene has been repeating itself, almost unchanged, for a very long time indeed. The horseshoe crab is often called a living fossil, for creatures almost identical to those on the beach today were crawling across the seabed more than four hundred million years ago, long before the dinosaurs, and they have outlasted them all.

Despite its name, the horseshoe crab is not a crab at all, but a distant relative of spiders and scorpions. Its most obvious feature is the large, curved shell that covers and protects its body like a helmet, from beneath which a long, pointed tail projects. That tail looks alarming but is quite harmless; the animal uses it not as a weapon but as a lever, to right itself when a wave has flipped it helplessly onto its back. Underneath the shell, the horseshoe crab has ten legs, which it uses both to walk and to push food towards its mouth. Perhaps its strangest feature, however, is invisible from the outside: its blood, which contains copper rather than iron, is not red but a startling shade of blue.

That blue blood has turned out to be extraordinarily valuable to human beings. It contains a substance that reacts to the presence of certain dangerous bacteria by forming a clot, and this reaction is astonishingly sensitive. For this reason the blood is used, all over the world, to test that vaccines, medicines and medical equipment are free of contamination before they are used on patients. To obtain it, horseshoe crabs are collected in large numbers, drained of part of their blood, and then returned to the sea. Many survive the ordeal, but a significant proportion do not, and even those that live are often weakened by it.

Blood collection is only one of the pressures the animal faces. For many years horseshoe crabs were gathered by the million to be ground up for fertiliser, and although that practice has largely ended, huge numbers are still taken to be chopped up for use as bait by fishermen. Their spawning beaches, meanwhile, are steadily being lost to seaside building and coastal defences, leaving the crabs fewer places to breed. As a result, their numbers have fallen in many areas.

The decline of the horseshoe crab matters for more than sentimental reasons, because other animals depend on it. Each spring, vast flocks of migrating shorebirds time their arrival on these coasts precisely to coincide with the crabs’ spawning, gorging themselves on the rich eggs to fuel the next stage of an immense journey. If the crabs fail, the birds go hungry, and their own long migrations are put at risk. The fate of the crab is thus tied to the fate of creatures far beyond the shoreline.

There is, at least, a growing effort to protect this ancient survivor. Limits have been placed on how many crabs may be taken, and a synthetic substitute for the blue blood has now been developed, which could one day remove the need to bleed the animals at all. Whether these measures come in time remains to be seen. It would be a strange tragedy if a creature that had endured for four hundred million years were to be pushed to the brink within the space of a single human century.

You should spend about 20 minutes on Questions 14–26.

Building with wood again

For most of the last century, the tall buildings that make up our cities have been built of two materials: steel and concrete. Wood was thought fit only for small houses, too weak and too dangerous for anything larger. That assumption is now being overturned. Across the world, architects are putting up apartment blocks, offices and even towers many storeys high built largely of timber – and they argue that wood may be one of the most important building materials of the century to come.

The timber used in these buildings is not the ordinary plank of old. It is a new kind of engineered wood, made by stacking many layers of timber and bonding them together with strong glue under great pressure to form massive panels and beams. Built up in this way, the material becomes remarkably strong – strong enough, its supporters say, to do the work once reserved for steel and concrete. Its great attraction, though, is environmental. Concrete and steel are among the largest sources of the carbon released by construction, whereas a growing tree pulls carbon out of the air and locks it away in its wood, so that a building made of timber actually stores carbon rather than releasing it, provided the forests it comes from are properly replanted. Wood is also far lighter than concrete, which means the foundations beneath a timber building can be smaller and cheaper. And because the great panels are cut to shape in a factory and simply bolted together on site, a timber building can go up remarkably fast, with far less noise and mess than a conventional one, and with fewer workers and lorries filling the surrounding streets. Many people find the exposed wood beautiful, too, warm where concrete is cold, so that the material need not be hidden behind other finishes.

For all these reasons, interest in timber construction has grown quickly, and a number of striking wooden buildings have been completed to show what the material can do.

The approach faces real resistance, however, and the first and loudest objection concerns fire. The idea of a tall wooden building strikes many people as dangerous, and the fear is understandable, even though engineered timber does not behave like a burning log: a thick timber beam chars on the outside and the charred layer then protects the wood within, so that such beams can in fact resist fire for a surprisingly long time. Persuading the public, and the authorities, of this is not easy. Regulations present a further difficulty, for in many places the building rules were written with steel and concrete in mind and simply do not allow tall timber structures, so that each new project must fight for special permission. Cost can be an obstacle too: the engineered wood is still relatively expensive to produce, and there are not yet enough factories making it. And wood has an old enemy in water: if the timber is allowed to get wet and stay wet, it can rot or grow mould, so the buildings must be very carefully designed and maintained to keep the moisture out.

Supporters accept these difficulties but believe they can be solved, pointing out that every one of them is a matter of engineering, habit or regulation rather than any fundamental flaw in the material itself. As the rules catch up, the factories multiply and the public grows used to the idea, they expect timber to take its place alongside steel and concrete as an ordinary way of building tall. None of this is to say that timber will replace steel and concrete entirely, or that the very tallest towers will soon be made of wood. But for the great mass of ordinary buildings of moderate height, it offers a way of building that is lighter, cleaner and faster. After a century in which wood was dismissed as a material of the past, it is beginning to look, once again, like a material of the future.

You should spend about 20 minutes on Questions 27–40.

The problem with the word ‘natural’

Few words in the language carry as warm a glow as ‘natural’. It appears on food and cosmetics, on medicines and cleaning products, and wherever it appears it promises something wholesome, safe and good. Its opposite, ‘artificial’, carries the reverse charge: cold, suspect, faintly harmful. We reach instinctively for the natural and recoil from the artificial. And yet, the writer will argue, this instinct is one of the least reliable guides we possess, for the word ‘natural’ tells us far less than we imagine, and often nothing useful at all.

The first difficulty is that nobody can quite say what the word means. Sometimes it means ‘not made by humans’; but by that definition a natural product would be one untouched by human hands, and almost nothing we buy qualifies. Sometimes it means ‘made from plants or other living things’; but plenty of things drawn straight from nature are among the most dangerous substances known. Sometimes it seems to mean nothing more than ‘the sort of thing I approve of’, a badge of virtue with no fixed content at all. The word slides from one meaning to another depending on what is being sold, and this vagueness is precisely what makes it so useful to those who wish to sell us something – for a word that can mean almost anything can be attached to almost anything.

The deeper problem is the assumption hidden inside the word: that what is natural is therefore good for us, and what is artificial therefore bad. A moment’s thought shows how shaky this is. Some of the deadliest poisons known come from entirely natural sources – certain plants, fungi and animals produce substances that will kill a person in minutes, and no one would call them healthy for being natural. Meanwhile a great many artificial things – clean drinking water treated with chemicals, life-saving medicines produced in a laboratory – are among the greatest blessings of modern life. Whether something helps us or harms us depends on what it actually is and how it is used, not on whether it happens to come from a plant or from a factory. The origin of a substance and its effect on the body are simply two different questions, and knowing the answer to the first tells us remarkably little about the answer to the second.

Why, then, does the natural exert such a pull on us? Part of the answer may lie in a general unease about the modern world, a sense that older ways were simpler and safer, and that the products of industry are not to be trusted. There is a grain of truth in this, but it hardens too easily into a prejudice, in which anything old and rural is assumed to be good and anything new and manufactured assumed to be suspect – a prejudice that pays no attention to the evidence in any particular case.

This matters because the worship of the natural can do real harm. People have refused proven medical treatments in favour of natural remedies that do nothing, and have sometimes paid for the choice with their lives. Shoppers pay more for foods labelled natural in the belief that they must be healthier, when very often they are not. And the word is used, again and again, to sell products on the strength of a feeling rather than a fact, distracting us from the questions that actually matter. Money that might have bought something genuinely better is spent instead on the reassurance of a label.

The writer is not arguing that natural things are bad, which would be just as foolish as the belief being criticised. The point is that the label itself tells us nothing worth knowing. Instead of asking whether a thing is natural or artificial – a question that turns out to be almost empty – we would do far better to ask what it is made of, what it does, and whether the evidence shows it to be safe and effective. Those questions are harder, and they cannot be answered by a single comforting word on a label. But they are the only questions that will actually tell us anything.