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
Newton was sitting under an apple tree ______ an apple fell onto his head.
#92858
A
when
B
while
C
after
D
before
Spacecraft “Discovery” has failed in the course of launch. ----_______? They have been preparing for the test.
#94908
A
How come
B
When
C
How
D
Why not
In no time _______ me if he had any further information for pig flu..
#95199
A
will he declare
B
he would notice
C
would he notify
D
he will note
I don’t think you will have any difficulty ______ a driving licence.
#95001
A
to get
B
in getting
C
for getting
D
get