问题
I was reading a novel_____ he was watchingTV
A:when
B:while
C:before
D:as
B:while
C:before
D:as
正确答案是：
同类题型
There are two rooms on the first floor, _____ is used as a guest room .
Since Tom ___downloaded a virus into his computer, he can not open the file now
Claudia, are you going to Jeff’s birthday party on Saturday—Unless I ______.
I’m so ______ to all those volunteers because they helped my terrible day end happily.