问题

He failed the mid-term examination and onlythen________how much time he had wasted.

A:he realized
B:did he realize
C:he had realized
D:had he realized

正确答案是：

同类题型

Wow! ______ beautiful the music is!—Yes. That’s my favorite.

Studies show that people aremore_________to suffer from back problems if they always sit before computerscreens for longhours.

hisplay, , is very wonderful:there are many interesting characters in it.

There’s no way of knowing why one man makes an important discovery another man, also intelligent, fails

There is going to be a wonderful party_______ the evening of October 1st, 2009.