张楠

Scientists are trying to make the deserts① 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. Now land desertification② is getting more and more serious. Scientists may not be able to change the deserts. People are doing bad things to the earth.

Some places on the earth dont get much rain. But they still dont become desert. This is because some green plants are growing there. Small green plants and grass are very helpful to dry places. Plants dont let the hot sun make the earth even drier. Plants dont let the wind blow the earth away. When a little bit of rain falls， the plants hold the water. Without the plants， the land can become a desert much more easily.

Choose the best answer.

1. Why can the land become a desert？

A. Some places dont get much rain.

B. Plants dont let the hot sun make the earth even drier.

C. People dont keep the earth well.

D. Scientists havent learnt enough about the deserts.

2. The underlined word “drier” means “____” in Chinese.

A. 更溫暖        B. 更湿润         C. 更炎热            D. 更干燥

3. Which is Not True？

A. The land never stops becoming desert.

B. Scientists ask the people to live in the deserts.

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 stop the wind from blowing the earth away.

C. They can keep the earth wet.

D. All the above.