问题

I had just stepped out of the bathroom and was busy drying myself with a towel ________ I heard thesteps.[ ]

A: while
B: when
C: since
D: after

正确答案是：

同类题型

find every possible way _____

The clothes are very nice.Can I___________

That T-shirt is not as_________ as this one.

Is that the reason __________ you are in favor of Obama for the second round?

They are discussing the problem right now It will ______ have been solved by the end of next week[ ]