1 . Playing cellphones in a dark room is harmful to our eyes.

A．dangerous

B．friendly

C．bad for

2 . —How is your daughter at school?   
—She is a good girl. She ________ herself.

A．is strict with

B．is bad for

C．is worried about

3 . Too much noise ________ our hearing. (对……有害)

4 . 吃太多垃圾食品有害健康。
Eating too much junk food ___________________ our health.

5 . Don’t read in the dark. It’s bad ________ your eyes.

A．at

B．for

C．in

6 . Eating too much sugar can be bad for your teeth.（改为同义句）
Eating too much sugar can be ________ ________ your teeth.

7 . 塑料袋对环境有害，所以我们应该用布袋来代替塑料袋。
Plastic bags are ________________ the environment, so we should use cloth bags instead of them.

8 . Tim, you have been watching TV for three hours. It’s bad ________ your eyes.

A．at

B．in

C．for

D．with

9 . 不要吃太多糖，对你没有好处。
Don’t eat too much sugar. It is ____________ ____________ you.

10 . 收集贝壳对环境有害。
Collecting shells ________ ________ ________ the environment.