1. 听材料，回答问题。

Mom, why can't I see the clock tower clearly from here? I could see farther yesterday.<br />Are you sure? Let me have a look.<br />I just can't see it clearly. There seems to be some kind of yellow fog in the air. It's very windy, too.<br />That's not fog. That is called a sandstorm. There is some sand and dust in the air when a sandstorm comes.<br />The storm keeps people from seeing things that are far away. This is very common in the north of China.<br />Oh, I see now. That's why they warned people here in Beijing not to go out without covering their faces today.<br />But why do we have sandstorms, Mom?<br />Oh, lots of reasons. But the loss and the balance of nature and a long drought are two big ones.<br />Then what can people do about it?<br />We should protect the forests and plant more trees.<br />Mom, why can't I see the clock tower clearly from here? I could see farther yesterday.<br />Are you sure? Let me have a look.<br />I just can't see it clearly. There seems to be some kind of yellow fog in the air. It's very windy, too.<br />That's not fog. That is called a sandstorm. There is some sand and dust in the air when a sandstorm comes.<br />There is some kind of yellow fog in the air when a sandstorm comes.<br />There is some kind of yellow fog in the air when a sandstorm comes.<br />There is some kind of yellow fog in the air when a sandstorm comes.<br />There is some kind of yellow fog in the air when a sandstorm comes.<br />There is some kind of yellow fog in the air when a sandstorm comes.<br />There is some kind of yellow fog in the air when a sandstorm comes.<br />There is some kind of yellow fog in the air when a sandstorm comes.<br />There is some kind of yellow fog in the air when a sandstorm comes.<br />There is some kind of yellow fog in the air when a sandstorm comes.<br />We should protect the forests and plant more trees.

1. （1） Where are the mother and her son?

   A . In a forest. B . Near the Yellow River. C . In Beijing.
3. （2） What's the trouble with the boy?

   A . He can't find his mother. B . There's something wrong with his eyes. C . He can't see the clock tower clearly.
5. （3） What have the people there been asked to do?

   A . To cover their faces when going out. B . Not to go out. C . To put on glasses when going out.
7. （4） What can people do to prevent sandstorms?

   A . Save water. B . Keep the balance of nature. C . Protect the animals.