Question

閱讀理解：There are plants in North Africa where great cities once stood. There were gardens and trees and grasses. But now these places are like deserts (a large land of sand). Scientists have begun to study this land to find out what happened. Many of them think the land died when the trees were cut down. Trees help other plants grow. Tree roots(根) hold the soil (the top of the earth where plants grow) in place. They keep the soil from blowing away. In forests, leaves on the ground keep rain-water from running off. Trees near farms protect (keep something safe) growing plants from strong winds.Once there were hundreds of farms in the southwest United States. Then the farms turned into fields of dry land. Trees might have saved these farms. But few trees grow in the dry Southwest. Now we try to save trees. In many forests, when a tree is cut down, a new tree is planted in its place. We do not want the land to die.The writer wants to tell us that ________.

1. A.
   farms are better than cities
2. B.
   there are no deserts in Africa
3. C.
   trees are important to the land
4. D.
   trees are quite important to American farms

Answer 1

C
這篇文章自始至終圍繞“樹對(duì)土地和農(nóng)業(yè)的影響”這一話題展開敘述，通過引用“北非”和“美國西南部”兩個(gè)典型例子予以左證，并詳細(xì)講述了樹根、葉是如何防止水土流失，以及森林是如何防止風(fēng)沙流動(dòng)，來證實(shí)樹木對(duì)土地的重要性。因此答案為C．