— I'd love to go to the party with you tonight.

— Oh, I'm sorry, there________be a party because of the coming exam.[ ]

A. mustn't  

B. needn't

C. can't  

D. oughtn't

公共场所集中空调系统的新风应从（）吸取。

A.楼道

B.室外

C.机房

D.天棚吊顶