When ____ to compare the education system of China and Britain, the professor gave no answer．
#81142
A
ask
B
asking
C
asked
D
to ask
推荐题目
Only after the woman had her own child ______how difficult it was to be a mother.
#81791
A
she realized
B
had she realized
C
she had realized
D
did she realize
–My room gets very cold at night.--__________.
#81946
A
So is mine.
B
So mine is
C
So does mine
D
So mine does
No sooner __________ these words than the warden hit him on the head with the soup spoon.
#80730
A
did he say
B
has he said
C
had he said
D
does he say
Only when I made it to the train station _______ that I had left my ticket at home.
#82660
A
have I realized
B
did I realize
C
had I realized
D
would I realize
_______, there would be no air around the earth.
#83707
A
There were no gravity
B
There was not any gravity
C
Were there no gravity
D
was there no gravity