Scientists say it may be five or six years _______ it is possible to test this medicine on human patients.
#33536
A
since
B
after
C
before
D
when
推荐题目
children believe they can succeed, they will never become totally independent.
#33346
A
If
B
Though
C
Unless
D
When
At the beginning of a speech, it is very important to grab the audience's attention and make them interested in ____ you have to say．
#31048
A
what
B
which
C
that
D
who
She had no sooner finished her task ________ it began to rain.
#29966
A
when
B
than
C
that
D
as soon as
— Why didn't you stop her going swimming alone? — She had left the room _____ I had time to do it．
#31660
A
after
B
before
C
till
D
as
he visited the new school, he showed great interest in everything he saw.
#31019
A
It’s the first time
B
For the first time
C
The first time
D
At first