1. fifteen-years-old → fifteen-year-old
2. 去掉to
3. being → to be （或去掉being）
4. troubles → trouble
5. to smoke → smoking
下列句中均有一处错误，请指出并改正。 1. Martin is a fifteen-years-old boy.
1. fifteen-years-old → fifteen-year-old
2. 去掉to
3. being → to be （或去掉being）
4. troubles → trouble
5. to smoke → smoking