They were surprised that a child should work out the problem____ they themselves could not.
#31497
A
once
B
unless
C
while
D
if
推荐题目
This is a difficult and stressful job, but one _____ you can really help people.
#33784
A
that
B
where
C
which
D
of which
cycling is a fantastic way to burn a few calories and save some money, there still exist risks．
#31065
A
Since
B
While
C
As
D
When
Why does she steal things _ she could easily afford to buy them?
#31052
A
when
B
while
C
unless
D
which
Colin was about to get off the camel ________ a child ran towards him.
#31552
A
while
B
when
C
as
D
since