肺通气的原始动力是
患者,女,32岁。孕46天,阴道不规则出血3天,色淡、质稀,下腹隐痛4天,神疲乏力,舌质淡,苔薄白,脉细滑无力。正确的诊断是
We see lightning before we hear the thunder because sound travels more slowly than light is.