You should not go rafting ________ you know how to swim.
#31441
A
if
B
if not
C
when
D
unless
推荐题目
The news ____is spreading around the airport is_____a heavy storm is coming.
#79948
A
what; /
B
that; that
C
/; that
D
that; which
You can go out, you promise to be back before 10 o’clock.
#31787
A
unless
B
as long as
C
because
D
since
It was for a lifetime of unselfish work among the sick natives ______ the old doctor deserved to be honored.
#33380
A
who
B
that
C
which
D
whom