We wish we ____ what you did when we were at high school

问题描述:

We wish we ____ what you did when we were at high school
A. didB. could have doneC. have doneD. should do

答案是B,对过去的事情的但愿.
在这里,could have done==had done--------但在你的语境裏面,一般是had done,尽管也可以是could have done.对过去的事情的但愿这怎样看?