问题

It may be 5 or 10 years __________ it is possible for people to find a space station on the moon

A:since
B:before
C:after
D:when

正确答案是：

同类题型

The little boy ___ his hiding place when coughed.

It was only after World War II had drawn toa close ______ in the United States.

Your Chinese is very good.- .

It was the third time this term that the teacher________with the naughty student

下列与“Pp”含有相同音素的是：__________.