It was not until the teacher had explained it three times _______ how to work out the problem.
A.did he understand | B.had he understood |
C.that he understood | D.that he didn’t understood |
推荐套卷
It was not until the teacher had explained it three times _______ how to work out the problem.
A.did he understand | B.had he understood |
C.that he understood | D.that he didn’t understood |