问题
We were having a meeting _________ suddenly someone knocked at the door.
A:because
B:when
C:as
D:while
B:when
C:as
D:while
正确答案是：
同类题型
Please don’t talk loudly here. The students _________the teacher in class.
If he takes on this work, he will have no choice but ______ an even greater challenge.＿
The large elephant _______ many elephants _______ looking for food for dinner. [ ]
__________ will the meeting last? –Less than an hour.
Common people always hold the view the experts say is right.