彬卅小站17岁裸身帅哥:哎！再次请大家帮帮忙！

1.-Why does she look so happy?
-Because she won the writing competition.
2.Dr Ma's duty is that teachs local doctors how to do the eye operation.
4.How to spend time wisely is a problem of teenagers.

1.-Why does she look so happy?
-It could be she won the writing competition.
2.Dr Ma's duty is that teachs local doctors how to do the eye operation.
4.How to spend time wisely is a problem of teenagers.

1.-Why does she look so happy?
-It could (be) because she won the writing competition.
2.Dr Ma`s duty is to teach local doctors (how) to do eye operations
3.-How many replies have you got?
-(None)
4.How to spend time wisely is a（teenagers'）problem.

不知道对不对……看看吧……

1-Why does she look so happy?
-Because she won the writing competition.
2.Dr Ma's duty is that teachs local doctors how to do the eye operation.
4.How to spend time wisely is a teenager problem.

1.could-is
2.to teach-teaching
3.nothing-none
4.teenagers-teenager