400V电源中断的现象、原因是什么?
哪项是毕Ⅰ式胃大部切除术的优点() ["适用于各种情况的胃十二指肠溃疡","吻合口张力较小","即使十二指肠溃疡未能切除,术后也能愈合","术后胃肠道功能紊乱较少","术后溃疡复发率较低"]
下列哪项不是椎管内麻醉对机体的影响() ["通气不足","呼吸抑制","血压下降","心率减慢","尿量增加"]
胃大部切除术,行胃空肠吻合,吻合口大小宜为() ["1~2cm","2~3cm","3~4cm","4~5cm","5~6cm"]
关于椎管内麻醉的叙述,不正确的是() ["椎管内麻醉就是指硬膜外阻滞","椎管内麻醉属于局部麻醉","椎管内麻醉作用对象是脊神经根","最细的交感神经纤维最先被阻滞","受阻滞区域出现肌肉松弛现象"]
我国南海地区夏季的水汽来源,主要来自()和()。