1. 去掉a，Martin isfifteen.3. seem 接不定式：He doesn't seem to be happy.4. trouble有时可数，有时不可数。作具体的某件麻烦事情时是可数, 例子： I find getting up early a great trouble.
我觉得早起床可不容易。作一般的麻烦,困难时是不可数.When he was young, he often got into trouble with the police5. give up 后加动名词：The doctor advised my father to give up smoking....
1. 去掉a，Martin is a fifteen.3. seem 后面应该是不定式：He doesn't seem to be happy.4. trouble是不可数名词，不加-s：When he was young, he often got into trouble with the police5. give up 之后必须用动名词：...
