Reading Practice Test 19

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

The lost cities of the Indus

A  In the 1920s, archaeologists digging in the plains of what is now Pakistan made a remarkable discovery. Beneath mounds of earth near the villages of Harappa and Mohenjo-daro lay the remains of large, carefully planned cities, built of fired brick and more than 4,000 years old. They belonged to a civilisation that had been completely forgotten — one that, at its height, covered a larger area than ancient Egypt and Mesopotamia combined.

B  The Indus civilisation, named after the great river along which it grew, flourished between about 2600 and 1900 BCE. Its cities were laid out on a grid, with wide main streets running north to south and east to west, and smaller lanes between them. Houses were built around courtyards, and most had their own bathrooms and toilets, from which waste flowed into covered drains running beneath the streets — a level of public sanitation that many cities in the world would not achieve again until the nineteenth century.

C  The most famous building at Mohenjo-daro is the so-called Great Bath, a large rectangular pool, about twelve metres long and seven metres wide, reached by steps at each end. Its floor and walls were made watertight with carefully fitted bricks and a layer of a natural tar called bitumen. Nobody knows for certain what it was used for, but many scholars believe it had a religious purpose, perhaps for ritual washing.

D  The people of the Indus were skilled traders. Their merchants used a standard system of weights, made from carefully cut cubes of stone, and their goods reached as far as Mesopotamia, where texts refer to a land called Meluhha that may have been the Indus region. Beads of a red stone called carnelian, made in Indus workshops, have been found in royal tombs in Mesopotamia, nearly 2,000 kilometres away.

E  Perhaps the greatest mystery of the civilisation is its writing. Thousands of short inscriptions have been found, most of them on small square seals carved with pictures of animals such as bulls, elephants and tigers. The seals were probably pressed into clay to mark goods or property. Yet the inscriptions are so short — rarely more than five signs — and no bilingual text has ever been found to compare them with, so the script has never been deciphered.

F  Equally puzzling is the absence of any obvious rulers. Unlike Egypt or Mesopotamia, the Indus cities have no great palaces, grand royal tombs or monuments celebrating kings, and very few weapons have been found. Some researchers believe the cities may have been governed by councils of merchants or religious leaders; others suspect that power was simply shown in less visible ways.

G  From around 1900 BCE, the cities were gradually abandoned. Earlier theories blamed an invasion, but there is little evidence of violence. Most researchers now believe that a combination of factors was responsible, including a shift in the course of rivers, the drying up of a major river system and a weakening of the monsoon rains over several centuries. As farming became harder, people seem to have moved east and south to smaller villages, taking their skills and traditions with them.

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

The age of the sun

A  In the space of a single generation, solar power has gone from an expensive curiosity to the cheapest source of electricity in history. In 1977, a solar panel capable of producing one watt of power cost around 77 dollars; today the same capacity costs well under a quarter of a dollar. Solar farms now stretch across deserts in China, India and the Middle East, and in many countries it is cheaper to build a new solar plant than to keep running an existing coal-fired power station.

B  At the heart of every solar panel are photovoltaic cells, usually made from thin slices of silicon, the main ingredient of sand. When sunlight strikes a cell, its energy knocks electrons loose from the silicon atoms, and because the cell is built in two layers with slightly different properties, these electrons are pushed to flow in one direction, producing an electric current. The effect was first observed by the French scientist Edmond Becquerel in 1839, but the first practical silicon cell was not made until 1954, at Bell Laboratories in the United States.

C  For decades, solar cells were so expensive that they were used mainly where there was no alternative — most famously, to power satellites in space. What changed was not a single breakthrough but a steady process of improvement and growth. As governments in countries such as Germany and China offered support to the industry, factories grew larger and more efficient, and each doubling of global production brought the price down by around a fifth. Economists call this pattern a ‘learning curve’.

D  Solar power has been particularly important for people who live far from electricity grids. In Bangladesh, a government-backed programme helped to install more than four million small solar home systems in rural households in the 2000s and 2010s, giving millions of families electric light for the first time. Children could study after dark, shops could stay open later, and families no longer had to rely on smoky kerosene lamps, which are a fire risk and harmful to health.

E  Solar energy does have one obvious weakness: the sun does not always shine. Output falls on cloudy days and stops completely at night, while demand for electricity is often highest in the evening. Managing this mismatch is now one of the main challenges for electricity systems. One solution is to store energy in batteries, whose prices have fallen almost as quickly as those of solar panels. Others include linking power grids over wide areas, so that sunny regions can supply cloudy ones, and encouraging people to use electricity at times when solar output is high.

F  There are also concerns about the materials needed. Manufacturing panels requires large amounts of energy, and some components contain metals whose mining can damage the environment. Old panels, which last around 25 to 30 years, will soon create a large stream of waste, and recycling them is still difficult and costly. Nevertheless, studies show that a typical panel produces the energy used to make it within two or three years, and its lifetime emissions are a small fraction of those from electricity generated by coal.

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

The puzzle of left-handedness

In every human society that has been studied, about one person in ten prefers to use the left hand. This proportion is remarkably stable: it appears in cultures as different as those of Europe, Africa and the Pacific, and studies of ancient tools and cave paintings suggest that it has hardly changed for thousands of years. Yet the fact that most people are right-handed is itself something of a puzzle, since most animals show no such strong preference at the level of the whole species.

For much of history, left-handed people faced suspicion and even hostility. In many languages, the word for ‘left’ carries negative associations — the English word ‘sinister’ comes from the Latin for ‘left’ — while the word for ‘right’ suggests correctness. Until the mid-twentieth century, schools in many countries forced left-handed children to write with their right hand, sometimes tying the left hand behind their backs. Psychologist Margaret Holt argues that this practice caused real harm, leading in some cases to stammering and difficulties with learning.

What decides which hand we prefer? It is clearly not simply a matter of choice, since a preference can often be seen in babies before birth, in the way they suck one thumb rather than the other. Genes play a part: left-handedness runs in families to some extent. However, geneticist Ravi Menon points out that the influence of genes is surprisingly weak. Rather than a single ‘left-handed gene’, dozens of genes each appear to have a tiny effect, and even identical twins, who share all their genes, often differ in which hand they use. Menon believes that chance events during the development of the brain in the womb are at least as important as inheritance.

Handedness is linked to the way the brain divides its work. In most people, the left half of the brain, which controls the right side of the body, is dominant for language. Among left-handers, this is still usually the case, but a larger proportion — perhaps 30 per cent — have language centred in the right half or shared between the two. Neuroscientist Claire Dubois suggests that this more varied organisation may help to explain why left-handers are over-represented in some fields, such as art and architecture, although she warns that the evidence is mixed.

Left-handers do seem to enjoy a genuine advantage in one area: one-on-one competitive sports. In tennis, boxing, fencing and cricket, left-handed players are far more common at the top level than in the general population. Sports scientist Tom Fischer explains this as a ‘surprise advantage’. Because most players spend their time competing against right-handers, they are less practised at dealing with left-handed opponents, whose shots and movements come from unfamiliar angles. In sports where players do not face each other directly, such as swimming or golf, no such advantage is found.

If left-handedness brings advantages, why has it not become more common? One theory is that it is maintained by a balance: being unusual helps in competition and conflict, but the advantage disappears if left-handers become too numerous. The world, meanwhile, remains largely designed for the right-handed majority, from scissors and tin-openers to the layout of computer keyboards. In my view, it is time we recognised that one person in ten is not a mistake to be corrected, but a normal and valuable part of human variety.