A.must be dropping

B.must have dropped

C.must have been dropped

D.must drop

请帮忙给出正确答案和分析，谢谢！

A.more than to go

B.more than going

C.than going

D.rather than to go

请帮忙给出正确答案和分析，谢谢！

A.learning history

B.history

C.study of history

D.history learning

请帮忙给出正确答案和分析，谢谢！

A. It’s a good idea.

B. Yes, we have to improve educational quality.

C. It is essential to make sure that every student learns.

请帮忙给出正确答案和分析，谢谢！