问题

What did you hear last night?-I seemed_________ someone knock at the door. [ ]

A: to be heard
B: to be hearing
C: to have heard
D: having heard

正确答案是：

同类题型

He has much money at the beginning of every month, but by the end of it he_____ have little left.

下列语句中，标点符号使用正确的一项是(　　)

It was July l,1997________saw the return of Hong Kong to the motherland. [ ]

Modern plastics can very high and very low temperatures.[ ]