.

On cold mornings, after washing your hair, you’d better dry it ______ using a hairdryer.

A．on

B．up

C．out

D．at

下列哪种抗生素可与核糖体50S亚基结合并抑制蛋白质的合成（）

A.四环素

B.氨苄青霉素

C.氯霉素

D.卡那霉素

E.新霉素