________himself with many optimistic people,the old man led a happy life.[ ]

A. Surrounded  

B. Surrounding

C. To surround  

D. Having been surrounded

男性，60岁。因慢性阻塞性肺病呼吸衰竭接受机械通气治疗，并发右下肺炎，病原学检查确认为铜绿假单胞菌。其抗菌治疗选择下列哪一组方案较合理（）。

A.头孢曲松联合阿米卡星

B.头孢曲松联合喹诺酮类

C.头孢噻肟联合哌拉西林

D.头孢噻肟联合庆大霉素

E.头孢他啶联合氨基糖苷类