The bridge is so important to the people here that once ________ it must be carried out without delay.
#97922
A
designs
B
having designed
C
designing
D
designed
推荐题目
While watching television, __________.
#88552
A
the doorbell rang
B
the doorbell rings
C
they heard the doorbell rings
D
they heard the doorbell ring
It can never be denied that        with a big family results in his quitting school.
#92612
A
having burdened
B
being burdened
C
to burden
D
burdening
No one can walk the wire in the air without a bit of fear unless ______ very young. 
#95230
A
having trained
B
trained
C
to be trained
D
being trained