Reading Practice Test 7

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

The history of chocolate

Chocolate today is a cheap and everyday treat, but for most of its history it was a rare luxury. Its story begins with the cacao tree, native to the rainforests of Central and South America, whose seeds — cacao beans — are the raw material of every bar and drink. The peoples of ancient Mesoamerica, among them the Maya and the Aztecs, were the first to turn these bitter beans into something worth consuming, thousands of years ago.

To these ancient civilisations chocolate was precious. The Aztecs valued cacao beans so highly that they used them as a form of money, and a frothy, bitter chocolate drink, flavoured with spices such as chilli, was reserved for priests, warriors and the nobility. Cacao was associated with the gods, and drinking chocolate was often part of religious ritual rather than everyday refreshment.

When Spanish explorers reached the Americas in the sixteenth century, they carried cacao back to Europe. At first the bitter drink was little liked, but once Europeans began to sweeten it with sugar it became wildly fashionable. For the next two centuries chocolate remained an expensive drink, sipped by the rich in special chocolate houses, much as tea and coffee were at the time.

Turning the beans into chocolate is a long process. After the ripe pods are harvested, the beans are scooped out and left to undergo fermentation for several days, a stage that is essential for developing the familiar flavour. The beans are then spread out to dry in the sun before being shipped to factories, where they are roasted to bring out their taste and to loosen their shells. The shells are removed to leave the inner ‘nibs’, which are ground into a thick, dark paste.

For most of its history, chocolate was only a drink; the solid bar is a surprisingly recent invention. In the nineteenth century a series of breakthroughs transformed it. Inventors found a way to press out some of the cacao's natural fat, or ‘cocoa butter’, producing a powder that made a smoother drink. Others learned to add this fat back, together with sugar, to make a paste that could be poured into moulds and set — the first true eating chocolate. Later, the addition of milk produced the mild milk chocolate popular today.

One further step made chocolate melt-in-the-mouth smooth. A process called ‘conching’, in which the chocolate paste is slowly kneaded and warmed for hours or even days, breaks down any grittiness and blends the flavours evenly. It was this refinement, together with the falling price of sugar, that finally turned chocolate from a costly delicacy into a treat that almost anyone could afford.

Chocolate's popularity has come at a cost, however. Most of the world's cacao is now grown not in the Americas but in West Africa, often on small farms where growers are paid very little. Concerns about poverty, and about the clearing of forests to plant more cacao, have led to campaigns for ‘fair’ and sustainable chocolate. The bar that began as a sacred drink of kings has become an everyday pleasure, but the story of how it reaches us is not always a sweet one.

You should spend about 20 minutes on Questions 14–26, which are based on the passage below.

Living light

A  On a dark night, a firefly blinks in a garden; far below the waves, strange fish glow in water that no sunlight ever reaches; and a breaking wave sometimes shines with an eerie blue light. All of these are examples of bioluminescence — the production of light by living things. Unlike the light of a bulb, this is a ‘cold’ light, giving off almost no heat, and it has evolved independently many times in creatures as different as bacteria, insects, jellyfish and fish.

B  The light is made by a chemical reaction. In most cases a substance called luciferin reacts with oxygen, a process speeded up by a helper molecule known as an enzyme. When the two combine, energy is released not as heat but as light. The reaction is astonishingly efficient: almost all of the energy becomes visible light, which is why so little warmth is given off. Different creatures use slightly different chemicals, producing light of different colours, though blue and green are the most common, since these travel best through seawater.

C  Living light serves many purposes. Fireflies flash in patterns to attract a mate, each species using its own rhythm of signals so that it can recognise its own kind. The deep-sea anglerfish dangles a glowing lure in front of its mouth to draw smaller fish within reach. Light can also be a defence: a sudden flash may startle a predator long enough for the prey to escape, and some squid release a glowing cloud, much like an alarm, to confuse an attacker while they slip away into the dark.

D  The great majority of glowing species live not on land but in the sea, and especially in its darkest depths. Below a few hundred metres, sunlight fades to nothing, and an animal's own light becomes one of the few ways to see, to signal or to hide. One of the cleverest tricks is called counter-illumination. Seen from below, a fish is normally a dark shape against the faintly lit surface far above; but by producing a soft light on its underside that matches the glow from the surface, the fish erases its own silhouette and becomes almost invisible to predators looking up.

E  Not every glowing animal makes its own light. Some cannot, and instead form a partnership with bacteria that can. These creatures house colonies of light-producing bacteria in special organs, feeding and sheltering them in return for their glow. Certain squid, for example, keep such bacteria in a pouch and use their light for counter-illumination, while the anglerfish's lure shines with the light of bacteria rather than its own. It is a neat arrangement in which both partners benefit.

F  Bioluminescence has proved surprisingly useful to human beings. By transferring the genes that produce luciferin into other cells, scientists can make those cells glow, and so follow processes that would otherwise be invisible — watching a disease spread through a body, for instance, or checking whether a particular gene has switched on. Such ‘tags’ have become an everyday tool in biology and medicine. Some researchers even dream of one day growing glowing trees to light our streets, turning one of nature's oldest tricks to a strikingly modern use.

You should spend about 20 minutes on Questions 27–40, which are based on the passage below.

Rethinking the working week

For over a century, the five-day, roughly forty-hour week has been the standard shape of working life across much of the world. Recently, though, a once-radical idea has been gaining ground: the four-day week, in which employees work one day fewer while keeping the same pay. What was once dismissed as a fantasy is now being tried seriously by companies, and even by governments, in a number of countries.

The case in favour rests largely on a single claim: that hours worked and work produced are not the same thing. Supporters argue that a well-rested employee working four focused days can achieve as much as a tired one stretched thinly over five, because much of a long week is wasted on distraction, needless meetings and simple fatigue. Give people less time, they say, and the unimportant tasks are quietly dropped while the essential work still gets done.

A growing body of trials appears to support this. In a number of large studies, companies that switched to a four-day week reported that their output held steady or even rose, while their staff were markedly happier and less stressed. Sick days fell, and fewer employees left, saving the considerable cost of hiring and training replacements. Tellingly, when these trials came to an end, the great majority of the companies involved chose to keep the shorter week rather than return to five days.

The benefits are not only financial. Employees with an extra free day report better mental and physical health, more time for family, exercise and rest, and less of the chronic exhaustion sometimes called ‘burnout’. There may be environmental gains too: one fewer commute each week means less traffic and lower emissions, and quieter roads on the extra day off.

Yet the idea is far from a cure-all. Critics point out that it suits some kinds of work far better than others. An office whose output can be measured in finished projects may adapt easily, but a hospital, a shop or a factory that must stay open cannot simply close for a day, and covering the missing hours may mean hiring more staff. There is also a risk that, rather than working less, employees merely cram the same workload into fewer days and arrive home more exhausted than before.

Coordination can be awkward as well. If different workers take different days off, teams may struggle to find times when everyone is available, and customers may be frustrated to reach a business that is closed. For these reasons, some organisations have preferred a gentler change — a slightly shorter week, or simply more flexible hours — rather than a full extra day away from work.

Perhaps the most valuable effect of the whole debate is that it has made people question something they had long taken for granted. The five-day week is not a law of nature but a historical arrangement, itself the product of long struggles to reduce working hours from the punishing schedules of the past. Seen in that light, the four-day week may be less a wild experiment than the next step in a very old trend — though whether it becomes the new standard, or remains suited only to certain jobs, is a question that only time and further evidence will settle.