Task 1
Direction: After reading the following passage, you will find 5 questions or unfinished statements, numbered 36 through 40. For each question or statement there are 4 chokes marked A), B), C) or D). You should make the correct choice and mark the corresponding letter on the Answer Sheet with a single line through the center.

At one time or another we have all stopped to think about the weather. Some days the weather is good. Some days the weather is bad. Still, there are days when the weather seems to change from hour to hour. A day that starts out fine might not stay that way. Sometimes a day that seems bad turns out better than you thought it would. There are ways of understanding the weather. One way is to study the clouds. No two clouds are ever alike. But it is still possible to group clouds and to give them names. We can recognize the different kinds of clouds and watch them for signs of changing weather. As a rote, the higher the clouds, the better the weather. And the lower the clouds, the worse the weather is likely to be. To predict the weather, there are three things about clouds you should look for: movement, color, and change. Clouds can tell you if storm is on the way. For example, small feathery cirrus clouds (卷云) can become thick and move lower. This means rain is on the way. If there is a sudden, cool breeze (微风) and a dark thunder (雷声) clouds appears, then a storm is about to break out.

This passage is mainly about ______.