问题

It suddenly occurred to him ____ he had left his keys in the office

A:of which the top
B:the top is
C:the top of which
D:with its top

正确答案是：

同类题型

lot of homework _________last weekend, Tom didn’t go to the movies with his friends.

We would have called a taxi yesterday if Harold ______us a ride home.

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Sorry, Bill, I can’t go fishing with you tomorrow.—- _________.

Missing school to watch the football is quite impossibleWhich of the following can replace the underlined part