1. 单句改错（找出错误并改正）

1. （1） Jenny has been attending on her sick mother for many years.

3. （2） The child was cured his bad habit with the help of his friends.

5. （3） Exposed to the polluted air did harm to his health.

7. （4） We got together at the night he returned from abroad.

9. （5） When will you have your homework hand in?