问题

Have you seen your friend off ?—YesI watched the train leaving the station it disappeared from sight

A:unless
B:as if
C:so that
D:until

正确答案是：

同类题型

Cultural exchange ________ betterunderstanding

Father put the ladder(梯子)_________ the tree to pick the apples for me.

, he can answer the difficult questions.

I had a pleasant winter vacation with my family in the north. —______.

I ________ have used the computer without asking you first.[ ]