问题
单项选择（每题1分）We must think twice _____ we make the final decision
A:when
B:while
C:until
D:before
B:while
C:until
D:before
正确答案是：
同类题型
It’s a fine day today. How about __________— Sounds great!
Is that Jack speaking? —Sorry, he _______ inHe _______ back in half an hour[ ]
When I was in kindergarten, I was often _____ by my teachers to be polite to the adults.
ou think George has passed the driving test—No. If so, he ______ his car to our college yesterday.