2019学年度人教版必修四Unit 2 Section VIUsing language课时作业

　　第二部分：阅读理解(共两节，满分40分)

　　第一节(共15小题；每小题2分，满分30分)

　　阅读下列短文，从每题所给的四个选项(A、B、C和D)中，选出最佳选项。

　　A

　　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 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 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 helpful to dry 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 a desert much more easily.

　　文章大意：由于土地沙漠化，农田面积在减少，如何使沙漠变良田，植被作用至关重要。科学家们正在为此努力。

　　21．Small green plants are very important to dry places because __D__.

　　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 the water

　　D．all of the above

　　解析：细节理解题。由原文第二段内容可知，A、B、C三项均可，所以选择D项。all of the above表示"以上所有的(选项)"。

　　22．Which is the main idea of the first paragraph？__B__

　　A．Scientists know how to change deserts into good land.

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

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

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

　　解析：段落大意题。由第一段和现实可知，土地沙漠化的速度要比科学家尽力使沙漠变良田的速度快，B项完整。其他三个选项都很片面，不能概括整个段落的含义。

　　23．After reading this passage，we learn that __A__.

A．plants can keep dry land from becoming deserts