COPD合并慢性肺心病，死亡的最常见原因是（）。
A.呼吸衰竭
B.消化道出血
C.心律失常
D.休克
E.电解质紊乱
参考答案：A
Lots of rescue workers were working around the clock,_____ supplies to Yushu,Qinghai Province
after the earthquake. [ ]
A. sending
B. to send
C. having sent
D. to have sent
最常见的动脉瘤（）
A.颈内后交通动脉瘤
B.前交通动脉瘤
C.大脑后动脉动脉瘤
D.大脑中动脉动脉瘤
E.椎基底动脉动脉瘤
