The old professor asked us ______ we read books in our spare time.
#31204
A
which
B
that
C
what
D
if
推荐题目
_______ you start, you should go ahead.
#31315
A
Once
B
Before
C
Until
D
Though
__________ he took part in the competition, he won a second prize. 
#33676
A
The first time
B
For the first time
C
At a time
D
At one time