I am against children to school before they are six.

A. used to read B. am used to reading

C. use to read D. have used to read

A. had seen

B. had been seeing

C. have seen

D. have been seeing

A.what

B.which

C.that

D.who

A.unless, don’t study

B.unless, study

C.if, study

D.if, not study

A. didn’t he

B. wouldn’t you

C. hadn’t he

D. don’t you

A. didn’t say

B. wouldn’t say

C. hadn’t said

D. don’t say

A. am going to

B. will

C. would

D. was going to

A. lose

B. lost

C. would lose

D. will be

A. although

B. nevertheless (然而、不过)

C. unless

D. Once (一旦)

A. by

B. under

C. until

D. up to