题目内容
Both warm-blooded and cold-blooded desert animals have ways to escape the desert heat.
Warm- blooded desert animals, such as rats and mice, rest during the day, often staying in cool
underground burrows. At night they search for food. Animals that are out during the day, such as
cold-blooded lizards and snakes, are active only for short periods. As their body temperature rises,
these reptiles(爬行动物) move into the shade in order to cool down. In the early evening, when
the sun grows weaker, the reptiles become more active and begin their search for food again.
Getting enough water to survive is a major problem for all desert animals. Some desert animals,
like desert birds, manage to find water holes. Other desert animals, such as the kangaroo rat and the
related jerboa, get water only from the food that they eat. Because these animals eat mainly dry seeds,
they must survive on a tiny amount of water.
Most deserts have only a small number of frogs and toads because these animals must be near
water to survive. Yet even these creatures have adapted(适应) to desert conditions. When small
amounts of water collect in temporary streams, the desert-living frogs and toads become active.
After a rainfall, they lay their eggs. The eggs grow into tadpoles in a few days and into adults in just
four weeks. When the puddles(水坑) dry up, the adult frogs or toads dig into the ground. Their metabolism(新陈代谢) slows, and they stay beneath the ground until the next rain, which may be as good as
a year away. Until then, their bodily activities continue at a reduced rate.
The camel - often called the ship of the desert - is one of the most successful desert animals. Camels
can go for long periods without water, but eventually they must drink. When water becomes available
to them after a long drought, they may drink 95 liters of water or more. When water is not available,
what helps camels survive the desert heat is the fat stored in their humps(驼峰). A camel's hump contains
about 12 kilograms of fat. Fat is rich in hydrogen. As the fat is digested, hydrogen from the fat combines
with oxygen in the air that the camel breathes. The result is H2O, or water. Each kilogram of fat that a
camel digests produces about a liter of water.
_____.B. it is easier to find water
C. they like the dark
D. they are less likely to be attacked at night
B. The kangaroo.
C. The frog.
D. The rat.
B. All the desert animals don't rest during the day.
C. Cold-blooded desert animals are out most of the day.
D. None of the cold-blooded desert animals go out during the day.
B. Desert Animals
C. How Desert Animals Get Water
D. Ways To Escape the Desert Heat
B. caves
C. rooms
D. openings
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