问题

D【解析】试题分析:考查连词:
A:until
B:once
C:if
D:unless
B:once
C:if
D:unless
正确答案是:
同类题型
you may have, you should gather your courage to face the challenge.
He was knocked down by a car ____ he saw it run toward him.
The number of people invited to the party 200 but a number of them ___absent for different reasons.
The committee __ over the problem among themselves for two hours.
__________ your teacher’s advice, I think, and the problems could be settled.