精品一区二区免费在线观看_国产精品久久久久久av福利软件_97成人精品区在线播放_国内成人精品一区

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

閱讀理解

　　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 desert in time.

　　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 drive. Plants don't let the wind blow the dirt（泥土）away. When a little of（一點兒）rain falls, the plants hold the water. Without plants, the land can become a desert much more easily.

(　　)(2)It is good to get rid of（消除）the grass in the desert

(　　)(4)It's important for us to plant trees and protect（保護）forests.

Scientists （科學家） 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 deserts all the time. Scientists may not be able to change the deserts. Scientists think that people make deserts. People are doing bad things to the earth.

Some places on the earth don’t get 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 helpful to dry (干旱的)places. Plants don’t let the hot sun make the earth even drier. Plants don’t let the wind blow the earth away. When a little bit of rain falls, the plants hold the water. Without plants, the land can become deserts much more easily.

1.Why can the land become deserts?

A. Some places don’t get much rain.

B. Plants don’t let the hot sun make the earth even drier.

C. People don’t keep the earth well.

D. Scientists haven’t learnt enough about the deserts.

2.Scientists are???????? to make the deserts into good land again.

A. carrying water? B. growing food? C. doing nothing????????????? D. studying a lot

3.Which is NOT true?

A. The land never stops becoming deserts.

B. Scientists ask people to live in the deserts and grow food there.

C. People do bad things to the earth.

D. Scientists may not be able to change the deserts.

4.Why are green plants and grass helpful?

A. They can hold the water.?

B. They can keep the earth wet.

C. They can stop the wind from blowing the earth away.

D. All the above.

5.Which is the best title（題目）for the passage?

A. The Desert Problem?????????

B. People Make Deserts

C. Green Plants and Grass???????

D. The Deserts, the Tree and the Water