[名词解释] 干啰音

急性肺源性心脏病最常见病因是（） ["ARDS","肺间质纤维化","肺动脉栓塞","重症肺炎","COPD"] 一般正常的Q波时限应（） ["<0.04s","<0.06s","<0.08s","<0.10s","<0.12s"] 胸膜摩擦音   漏斗胸 正常的Q波振幅应小于同导联中R波的多少（） ["1/2","1/3","1/4","1/5","1/6"] 干啰音