问题

I met a friend of mine _____ I was walking in the park.
A:before
B:when
C:after
D:if
B:when
C:after
D:if
正确答案是:
同类题型
In the exam, the_________you are, the_________mistakes you’ll make.
It’s too difficult for you to answer. —Why ____ the teacher for help?[ ]
I usually go to school by bike. — ______.
The flight to New York was ________ because of the heavy fog.
There is a ticket on the floor, is it yours? —Oh, yes, it’s mine. —Let me _____for you.