Reading Comprehension

Read the passage carefully. Then answer the questions below.

Deserts have come to symbolize places of extreme heat. The fact is, most of the famous deserts of the world are places where the thermometer goes bubbling away and where the sun beats down without mercy. But this does not mean that a desert must be a place where it is always hot. If you find out the definition of a desert, you will understand why this is so.

A desert is a region where only unique forms of life can exist because there is a shortage of moisture. There simply is not enough rainfall in a ‘hot’ desert, so the definition holds. But suppose there is a region where all water is frozen solid and cannot be used by plants. This satisfies the definition too. Only it would make this a ‘cold’ desert. Many people do not know that much of the Arctic is really a desert. There is very little rainfall a year, and most of the water is frozen, while the great Gobi Desert in the middle of Asia is bitterly cold in the wintertime.

Most of the dry, hot deserts with which we are familiar are found in two belts around the world, just north and south of the Equator. They are caused by high atmospheric pressures that exist in those areas, which prevent rain from falling. Other deserts, which are found farther away from the Equator, are the result of being in ‘the rain shadow’. This is the name for an effect caused by mountain barriers that catch rainfall on their seaward side and leave the interior region dry.

Deserts differ significantly in appearance. Where sand is abundant, the winds may build sand hills or dunes. These are sand deserts. Rock deserts consist primarily of bare rock, which forms fantastic cliffs and hills. No great rivers originate in deserts. But a river may rise in moist areas and cross great deserts on its way to the sea. The Nile, for example, flows through the desert region of the Sahara.

The animals that exist in the desert are those that have managed to adapt themselves to its conditions. They must be able to do without water for long periods or reach water holes at great distances. The camel, for example, is highly adapted to desert life. It has padded feet to walk on sand, a water-storing stomach, humps of fat as a reserve supply of energy, and nostrils that can be closed to keep out sand during windstorms.

Many of the smaller desert creatures need to drink no water at all. They get what liquid they need from the sap of food plants and night dew on leaves or stones.