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
—She should have been informed of the meeting.—______，but she wouldn’t like to attend this meeting.
#92266
A
Yes，she should
B
So she was
C
So was she
D
So it was with her
I definitely appreciate ____ when I can walk away from my computer after a long day of typing and have pain-free arms!
#91935
A
that
B
it
C
you
D
one
Not until he questioned the manager several times ___________ that the engineer-in-chief had gone to an important meeting.
#93124
A
did he tell
B
he told
C
was he told
D
he was told
The employers often give the job to __________ they believe have work experience with a strong sense of duty.
#93037
A
whoever
B
those who
C
who
D
whomever
Loulan is believed __________ over by sandstorms gradually from AD200 to AD400.
#92411
A
to cover
B
to be covered
C
to have covered
D
to have been covered