混合气体总压力(P)与各组成气体分压(P1P2…Pn)的关系是() ["A．P＝P1·P2…Pn","B．P=n(P1+P2…Pn)","C．P=P1+P2…Pn","D．P=P1·P2…Pn／n","E．P=P1+P2…Pn／n"]
0．25MPa(绝对压)相当于() ["A．水下15m处的压力","B．水下25m处的压力","C．水下35m处的压力","D．25kg／cm2的压力","E．1800mmH2O的压力"]
简述食管的三个生理性狭窄及其临床意义。
呼吸周期
女，30岁，咳痰，咯血，结合图像，最可能的诊断是() ["A．肺部感染","B．支气管扩张并感染","C．支气管囊肿","D．间质性肺炎","E．肺结核"]
霍乱的并发症是()中毒性菌痢的并发症是()伤寒的并发症是()阿米巴痢疾的并发症是()
