引起COPD的外在因素是（）。
A.感染
B.理化因素
C.空气污染
D.吸烟
E.蛋白—抗蛋白酶系统失衡
参考答案：A, B, C, D
Each fireman’s outfit and its spare equipment on a vessel must be stowed（）.
A.in a locked cabinet in the machinery space
B.in an unlocked cabine in the machinery space
C.in a separate and accessible location
D.at a fire hydrant location
干流量
