问题

It was not until the teacher had explained it threetimes _______ how to work out the problem.

A:did he understand
B:had he understood
C:that he understood
D:that he didn’t understood

正确答案是：

同类题型

How far is Yuhua Middle School from here——It’s around five minutes’walk.

– How long has this church been inservice—-_________1682, I’m afraid

Whose dog is this—It’s . Both of like it very much.

you keep silent a few minutes,please You are here_________.

There are some treesourclassroom.