IELTS Academic Reading Test 4 with Answers

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

The comeback of the humble oyster

For most people today the oyster is a luxury, an occasional treat eaten from the half-shell in expensive restaurants. It is easy to forget that for centuries it was the opposite: a cheap and plentiful food that filled the stomachs of the poor in the port cities of Europe and North America. Great reefs of oysters once carpeted the shallow coastal waters and river mouths of both continents, so dense in places that they were a hazard to shipping. Then, within the space of a hundred years, almost all of them were gone. The story of the oyster is one of spectacular collapse – but it is now, in a small way, becoming a story of return.

The oyster is a far more remarkable creature than its plain appearance suggests. It begins life as a free-swimming larva no bigger than a speck of dust, drifting with the current until it finds a hard surface – most often the shell of another oyster – onto which it cements itself, there to remain, immobile, for the rest of its life. From that fixed position it feeds by drawing seawater through its body and straining out the tiny particles suspended in it. A single adult can filter as much as two hundred litres of water in a day, removing not only its food but also silt, algae and pollutants, so that water passing over a healthy reef emerges dramatically clearer than it went in. Because the animals settle on one another, generation upon generation, they build up over time into vast reefs, and these reefs are themselves an adaptation of a kind: they provide shelter and nursery grounds for crabs, fish and countless other species, and they act as a natural breakwater, absorbing the force of storm waves before they reach the shore.

None of this saved the oyster from human appetite. As the cities of the nineteenth century swelled, the demand for cheap food grew with them, and the reefs were dredged on an industrial scale, hauled up faster than they could ever regrow. Overharvesting was only the beginning. The rivers that fed the estuaries carried an ever heavier load of sewage and, later, of chemicals, and the resulting pollution poisoned the beds that remained. Sediment washed from ploughed fields and building sites smothered the young oysters before they could establish themselves. And disease, spreading easily through the crowded survivors, finished off many of the beds that harvesting and pollution had spared. By the middle of the twentieth century the once-limitless reefs had shrunk to a tiny fraction of their former extent.

The loss was not only of a food source. As the reefs disappeared, so did their hidden services. Coastlines that had been sheltered by oyster beds became more exposed to erosion. Waters that the oysters had once kept clear grew cloudy and choked with algae. The fish and crabs that had sheltered among the shells declined along with them.

It is precisely these services, rather than the oyster as a delicacy, that have inspired the recent efforts to bring the reefs back. In harbours and estuaries on both sides of the Atlantic, conservation groups are rebuilding oyster beds, not to be eaten but to clean the water and protect the shore. Often the work begins with something surprisingly ordinary: empty shells, collected in their thousands from restaurants and returned to the sea to give the next generation of larvae a surface on which to settle. Volunteers lower cages of young oysters from harbour walls and jetties; schools and community groups raise them and monitor their growth. The scale is still modest, and the reefs of the past will almost certainly never return in full. But in waters that had been lifeless for decades, the oyster is quietly getting back to work.

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

Lighting the streets after dark

The city of Norwich, in the east of England, has become an unlikely testing ground for a new approach to a very old problem: how to light a city at night. For more than a century, the answer seemed obvious – the more light the better. Brighter streets were thought to mean safer streets, and towns competed to banish the dark. But a growing number of researchers now argue that in flooding the night with light we have created problems of our own, and Norwich is one of a handful of places trying to put that right.

The scheme replaces the old orange street lamps with modern lights based on LEDs. The advantages are immediate and practical. The new lamps use a fraction of the electricity of the ones they replace, which sharply reduces both costs and carbon emissions. They also last far longer, so the council spends less on sending crews out to change bulbs. But the feature that most interests the researchers is control. Unlike the old lamps, which could only be switched fully on or fully off, each new light can be dimmed remotely and precisely, its brightness adjusted street by street and hour by hour from a central computer.

That control is being used to tackle a problem that has only recently been taken seriously: light pollution. Artificial light thrown upward and outward, rather than down onto the pavement where it is wanted, spills into the sky and washes out the stars, and it reaches far into the surrounding countryside. For wildlife the consequences can be severe. Many insects are drawn helplessly toward bright lamps and die there in huge numbers; the birds that feed on them are affected in turn. Newly hatched turtles, on lit coastlines elsewhere, crawl toward the glow of the streets instead of the sea. And there is mounting evidence that artificial light disrupts the natural rhythms of human beings too, interfering with the sleep of those who live beneath the brightest lamps.

The Norwich lights are designed to reduce these harms. The new lamps are shaped and angled so that they cast their light downward, onto the road and footway, and almost none escapes upward into the sky. Their colour has been chosen with care as well: a warmer tone that is thought to be far less disturbing to insects and other animals than the harsh blue-white light that early LED schemes often produced. And in the quietest hours, long after midnight, the lights across residential districts are automatically dimmed to a low level, brightening again only if a sensor detects someone approaching.

The results so far have been encouraging, but the scheme has not been without difficulty. Some residents, accustomed to a century of ever-brighter streets, complained at first that the dimmed roads felt gloomy and, they feared, less safe, and the council found that explaining the reasons behind the change was as important as the change itself. The equipment, too, is expensive to install, and although the savings on electricity eventually cover the cost, the initial outlay is high – a serious obstacle for councils with little money to spare. The controls have occasionally failed, leaving sections of a street too bright or too dark until an engineer could be sent. And gathering firm evidence about the effects on wildlife has proved slow and painstaking work, since animal populations vary for many reasons and the influence of lighting is hard to separate from the rest.

Even so, the direction of travel seems clear. Studies carried out during the scheme have found no rise in road accidents or crime on the dimmed streets, easing the fear that darker must mean more dangerous. Other towns and cities have sent observers to see how the system works, and several have begun schemes of their own. After a hundred years spent trying to abolish the night, some cities are, cautiously, learning to let a little of it back.

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

The trouble with the to-do list

There are few objects more reassuring than a freshly written to-do list. On the page, the chaos of the day resolves itself into a neat column of tasks, each waiting patiently to be crossed off. The list promises order, control and, above all, the satisfying prospect of completion. It is no surprise that the list has become the central instrument of modern productivity, endlessly refined by apps and experts. And yet, for something so universally trusted, it works remarkably badly. Most of us end most days with more items on the list than we began with, and the promised sense of control rarely arrives.

The trouble begins with the way a list flattens the world. Written down one beneath another, all tasks come to look alike: ‘reply to email’ sits level with ‘change career’, and each is reduced to a single tickable line. But these things are not alike at all. Some take two minutes and some take two years; some are trivial and some will shape a life. By stripping away this difference, the writer argues, the list quietly encourages us to treat all tasks as equal – and, human nature being what it is, to reach first for the small and easy ones, precisely because they can be finished and crossed off. The hard, important, unshapely work – the kind that cannot be reduced to a single line – is postponed, day after day, while we busy ourselves clearing away the trivial.

There is a deeper problem still, and it concerns the nature of time itself. A list is built on a hidden assumption: that the future is a container waiting to be filled, and that with enough planning we can fit into it everything we intend to do. But this is a fantasy. The supply of possible tasks is effectively infinite, while the time available is stubbornly finite, and no amount of clever organisation can change that arithmetic. The person who works through their list faster does not, as they hope, arrive at a clear horizon; they simply create room for new demands, which rush in to fill the space. Efficiency, pursued in this spirit, becomes a trap: the more we get done, the more we find there is to do.

This helps explain a phenomenon that puzzles many people. The busiest and most capable individuals – those who answer every message and complete every task – often find that their reward is not freedom but a still heavier load. Their very reliability marks them out as people to whom more can safely be given. The colleague who clears their inbox by lunchtime is the colleague who, by the afternoon, has the fullest inbox of all. Meanwhile the genuinely important projects, the ones no one is chasing and no one has assigned, wait quietly in the background, because they never generate the little pings of demand that a list is so good at capturing.

What, then, should we do? The writer’s answer is not to abandon lists but to change what we ask of them. A list, on this view, is useful as a place to set down what is on our minds, so that we need not carry it all in our heads; it is worse than useless as a promise that everything on it will be done. The first task is not to organise but to choose – to accept, at the outset, that most of what could be done will not be done, and to decide, deliberately and in advance, which few things genuinely matter. Only then does the list become a servant rather than a master.

None of this offers the comfort that productivity culture promises. There is no arrangement of tasks, no app, no system, that will allow us to do everything; the sooner that hope is given up, the better. But there is a quieter consolation in its place. Once we stop trying to get on top of everything – an aim that was never possible – we are free to give ourselves fully to the few things that count. The list, shrunk back to its proper size, stops being a monument to all we have failed to do, and becomes, at last, merely a tool.