问题

We were about to start out________ our friends calledus up from Shanghai.
A:when
B:while
C:until
D:before
B:while
C:until
D:before
正确答案是:
同类题型
If we don’t often use the newly learned words, we’ll _____ forget them.
My father walked me to the bus stop and waited with me _______ the bus arrived.
_____ the flight to New York will be delayed is ____ I’m especially worried about.
Ihavenoidea____________ tell herthebadnews.— I think tomorrow is the best time.