—Sorry for the delay.I got lost in the mountain.

—That's OK.You're safe and that's what________.

A．does　

B．works

C．stays　

D．counts

革兰阳性球菌感染可选用()

A．青霉素

B．丁胺卡那霉素

C．克林霉素

D．可乐必妥

E．万古霉素