为预防产后出血的发生，下列哪项是正确的() ["A．第二产程时，宜于宫缩时娩出胎儿头部","B．产后2小时内应在产房内观察宫缩及阴道流血情况","C．胎儿娩出后，立即按摩子宫帮助胎盘娩出","D．胎儿即将娩出时，肌注缩宫素","E．以上都不是"] 下列哪项成分在反流物损伤食管粘膜中起主要作用() ["A．胃内容物","B．胰液","C．胃酸和胃蛋白酶","D．胆汁","E．胆酸"] 关于食管哪项是正确的() ["A．食管下括约肌长约4～5cm","B．食管下括约肌静息压为15～35mmHg","C．食管继发性推进蠕动由吞咽动作引发","D．正常吞咽时食管下括约肌松弛时间少于8s","E．胆囊收缩素(缩胆囊素)可使食管下括约肌压力升高"] 诊断反流性食管炎最准确的方法是() ["A．食管测压","B．24小时食管pH监测","C．食管钡餐检查","D．内镜检查","E．食管滴酸试验"] 胸骨后疼痛伴烧灼感应首要考虑() ["A．胃食管反流病","B．冠心病、心绞痛","C．慢性胃炎","D．咽喉炎","E．消化性溃疡"] 正常1ES的静息压是()