问题

He failed the mid-term examination and only then _____ 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

average citizen, always thinksof_____ he can do more for the people．

Have you ever heard the song called “When I am old!”–_________.I am going to listen to it sometime next Sunday.

.I find ____very important to study English well.

My brother _____ the Youth League since1990

Have you _______some new ideas—YeahI’ll tell you later