题目内容：

A mobile phone is very useful. And many students have great      playing with it. But it does      to our health a lot.

If you have a mobile phone, it is necessary to know about the      of using it and learn how to enjoy your phone safely. Sending messages can be a wonderful way to keep in touch with your friends. But you      receive some cheating messages.     , you may get a message saying that you have won a big prize (奖品). Don’t believe it.

Some students like listening to the music on the phone      walking. It’s very    because there are so many cars and buses on the road. Remember not to talk on the mobile phone too often or too long. Your parents will be angry if you      too much money. Last,      your mobile phone when you sleep. The      of rubbish messages may wake you up. What’s more, the radiation of the cellphone is harmful to your brain.

1.A. trouble  B. fun     C. difficulty  D. sadness

2.A. harm   B. harmful  C. good    D. well

3.A. happiness B. unhappiness    C. advantages  D. disadvantages

4.A. always   B. never       C. already  D. probably

5.A. Such as  B. For instance C. Instead of  D. In fact

6.A. while   B. until    C. before       D. after

7.A. safe    B. dangerous  C. careful   D. exciting

8.A. cost    B. take   C. spend   D. have

9.A. turn up  B. turn down  C. turn off  D. turn on

10.A. sounds  B. noise          C. voice   D. pronunciation