作为药品生产和经营企业的

A．营销手段

B．新药研究开发手段

C．生产手段

D．营销目标

E．生产目标

— 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