1. 根据句意及汉语提示填空。

1. （1） No one knows clearly when the next (地震) will happen.

3. （2） I bought a mobile (电话) for the old for my father on his seventieth birthday.

5. （3） Many students can't see the black board clearly because a tall boy sits in the (中间) of the classroom.
   

7. （4） The first thing we should do is to (保持) calm when an earthquake happens.

9. （5） We should learn something to (保护) ourselves from a fire.