Scientists say it may be five years ______ it is possible to test this medicine on human patients．
#31988
A
since
B
until
C
before
D
when
推荐题目
It is difficult for us to imagine_____ life was like for slaves in the ancient world.
#30005
A
where
B
what
C
which
D
why
____________ the weather has improved, the game will be held as planned.
#31656
A
While
B
Since
C
If
D
Unless
---Is that the small town you often refer to?---Right, just the one _______ you know I used to live for years.
#34822
A
that
B
which
C
where
D
what
---The Bird's Nest, isn't it?---Yes. It's ___________we visited during our stay in Beijing.
#79754
A
where
B
what
C
when
D
That
The young couple are trying to save as much as possible ________ they can afford a flat by the end of next year．
#33431
A
so that
B
even though
C
in case
D
as if