It never _____ humans until the mid1990s that some animals can be cloned.
#92718
A
occur
B
is occurred
C
occurred to
D
occurred
推荐题目
Can you imagine the great difficulty he had ________ his driving test last week?
#92046
A
pass
B
to pass
C
passing
D
passed
The train ________ arrive at 11∶30, but was an hour late.
#94900
A
was about to
B
was likely to
C
was supposed to
D
was certain to
When I returned to my study, I found the floor thoroughly______and all my books______according to the types of books
#95019
A
changing; ranging
B
changed; ranging
C
have changed; ranged
D
has changed; ranged
-Jim should have been informed of the wedding place. -________but he simply forgot about it.
#91983
A
So he had
B
So had he
C
So was he
D
So he was .