A desert is a very dry land where there is hardly any rain. In the day, it can be so hot that you could fry an egg on the ground. But during the night it is sometimes so could that water would turn into ice.






Many desserts are covered in sand. But some have mountains, rocks, or lakes that have dried up in the heat. The Great American Dessert has cliffs(悬崖) that have been made into amazing and beautiful shapes by the wind. The Sahara Desert in Africa is mostly sand. The Australian Desert has red sand.
Sometimes it does not rain for a whole year in the desert. But there is water deep under the ground and some plants have roots that go very deep to find it. Other plants have roots that spread out(延伸) a long way so they can suck up the rain as soon as it falls.
One desert plant is the cactus, which has long, spreading roots. The cactus stores water inside its hard skin. This skin protects it from heat and cold.
Camels are a bit like cactus plants! They store water too—inside their bodies. They have special fur which protects them from the sun during the day and keeps them warm at night.
Some other animals live in deserts, too. They have to be very good at seeing and hearing because most of them only come out at night. This is why many desert animals have extra big eyes or ears.
A desert fox has bigger ears than a normal for. A gerbil has huge eye, so that it can see at night. It stays cool in the day by staying underground, like most desert animals.
Some people live in the desert but they always make their homes near an oasis. An oasis is where water comes from an underground river. Near an oasis, people can grow lots of plants and keep animals.
Life is hard in the desert, for people, animals and plants. But desert people like to live there.
【小题1】A desert is very dry because__________.

Have you ever seen a horse with toes? Millions of years ago, horses had many toes. They had four toes on each front foot. They had three toes on each back foot. The horses were smaller than cats.

These small horses lived in the forest. Their many toes helped the horses run over the soft wet ground.

It was very hot in the forest. But the weather changed. It became cold. Many trees couldn’t live in cold weather. The trees died and fell. Forests became open field. The sun made the ground dry and hard. Horses began to change too. They began to get bigger. This took a long time. On the dry hard land, horses needed only their middle toes for running. At last their middle toes became hard.

1.Long ago, the horse had four toes on each of its __________.

A. back feet B. front feet C. right feet D. left feet

2.The cats were __________ the horses at that time.

A. as big as B. smaller than C. bigger than D. as small as

3.When the weather changed, __________.

A. many trees grew well in cold weather

B. animals began to change too

C. cats were older than the horses

D. horses were the same as they are