问题

I failed in the final examination last term and only then _______ the importance of studies.

A:I realized
B:I had realized
C:had I realized
D:did I realize

正确答案是：

同类题型

Nowadays the power of the wind is being ________ to generate electricity.[ ]

______ there is no water left on the earth —I really don’t know.

. The party last night was ____ success. Wesang and danced until it came to ____ end at :.

It’s 7:15 now. We must go to school.

Hi, Lucy. Your skirt is very nice.—____