问题

It took me a long time before I was able to fully appreciate what they ______ for me

A:had done
B:did
C:would do
D:were doing

正确答案是：

同类题型

Now a lot of new technologies can ___ problems in industry.

This is a cheap and simple process(过程), ____ ,there are dangers.

My shoes are cheaper than ________.

May I listen to the music here, Mr. White—Sorry, you’d better itlike that.

This is the first time that I _____ at the meeting