问题

I was about to give up my effort to solve a problem __________ a good idea struck me

A:when
B:while
C:until
D:before

正确答案是：

同类题型

My mother is a full-time tour guide but she dislikes travelling much.—__________.

Kathy __________a lot of English idioms by watching documentaries made by BBC. [ ]

______, he makes little progress. So he is trying new methods of study. Which of the following is WRONG?[ ]

_____ to him for what I said.

It’s said that an earthquake hit Japan the other day.—______ bad news! Let’s bless for the people there.