Question

Scientists are trying to make the deserts 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．

Why is more and more land becoming desert？ 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 important to dry places． Plants don't let the sun make the earth even drier． Plants do not let the wind blow the dirt away． When a bit of rain falls， the plants hold the water． Without plants， the land can become desert more easily．

1.Deserts _______．

A． never have any plants or animals in them

B． can all be turned into good land before long

C． are becoming smaller and smaller

D． get very little rain

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 soil 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 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．

Answer

1.D

2.D

3.C

4.B

【解析】

试题分析: 本文讲述了科学家们在试图把沙漠变回农田，他们想把水引到沙漠，人们就可以在那里生存种植作物了，但沙漠一直在增多。植被可以防风固沙，留住雨水

1.D考查细节题：从第一句话：They want to bring water to the deserts， so people can live and grow food. 可知沙漠的水很少，故选D项。

2.D 考查细节理解题。根据第三段提到Small green plants and grass are very important to dry places． Plants don't let the sun make the earth even drier． Plants do not let the wind blow the dirt away． When a bit of rain falls， the plants hold the water．可知三个原因都有，故选D项。

3.C 考查细节理解题。根据第一段提到Scientists may not be able to change the desert in time科学家不可能及时地改变沙漠，可知人们没有按照科学家所说的去做，故选C项。

4.B 考查细节理解题。根据第一段提到科学家努力把沙漠变成土地，为了做了很多的努力，但越来越多的土壤沙漠化，科学家不能及时的进行改变，故选B项。

考点 ：环保类阅读。