— I was told to be here at this time.

— Sorry, you ______. I forgot to tell you we've changed the plan. [ ]

A. must

B. may

C. can't

D. needn't

在肺组织中浓度较高的抗生素是( )。

A．红霉素
B．琥乙红霉素
C．克拉霉素
D．阿齐霉素
E．罗红霉素