Scientists are trying to make the deserts（沙漠）into good land again. They want to bring water to the deserts, so people can live and grow food. They are learning a lot about the deserts. But more and more of the earth is becoming desert all the time. Scientists may not be able to change the deserts. People are bad things to the earth.

Some places on the earth don’t get much rain. But they still become deserts. This is because some green plants are growing there. Small green plants and grass are very important to dry places. Plants don’t let the wind blow the soil（土壤）away. When a bit of rain falls, the plants hold the water. Without plants, the land can become a desert much more easily.

(     ) 1. Deserts________

A.      get very little rain

B.      never have any plants or animals in them

C.      can all be turned into good land before long

D.     both A and C

(    ) 2. Small green plants are very important to dry places because______

A.      they don’t let the sun make the earth even drier

B.      they don’t let the wind blow the earth away

C.      they hold water

D.     all of the above

(    ) 3. Land is becoming desert little by little because________

A.      plants can’t grow there

B.      there is not enough rain

C.      people haven’t done what scientists wish them to do

D.     scientists know little about the deserts

(    ) 4. Which is the main（主要的）idea of the first paragraph?

A.      Scientists know how to change desert into good land

B.      Land is becoming desert faster than scientists can change it back into good land

C.      If scientists can bring water to desert, people can live and grow food there

D.     More and more places are becoming deserts all the time

(    ) 5. After reading this, we can learn that _______

A.      plants can keep dry land from becoming desert

B.      it is good to get rid of the grass in the deserts

C.      all places without much rain will become deserts

D.     it is better to grow crops（谷物）dry land than to grow grass

阅读理解

　　Scientists are trying to make the deserts into land again. They want to bring water to the deserts, so people can live and grow plants. They are learning a lot about the deserts. But more and more of the earth is becoming deserts all the time. Scientists may not be able to change the deserts in time.

　　Why is more and more land becoming deserts? Scientists think that people make deserts. People are doing bad things to the earth.

　　Some places on the earth don't get very much rain. But they still don't become deserts. This is because some green plants are growing there. Small green plants and grass are very important to dry places. Plants don't let the hot sun make the earth even drier. Plants don't let the wind blow the dirt（土）away. When a little bit of rain falls, plants hold the water. Without plants, the land can become a desert more easily.

判断下列句子是否符合短文内容，符合的用“T”，不符合的用“F”表示。

1. Deserts get very little rain.　　  

(    )

2. Land is becoming deserts little by little because scientists know little about the deserts.　　

(    )

3. Plants can hold water and protect dry land from becoming deserts.

(    )

4. All places without much rain will become deserts.

(    )

5. Scientists are trying to change deserts into good land.

(    )