酸洗段工艺速度最大为()。 ["270m/min","320m/min","700m/min","1470m/min"]
500kV母线正常运行的电压不超过额定电压()。 ["20%","15%","10%","5%"]
关于不协调宫缩乏力,下列哪些正确:() ["多属原发性宫缩乏力","宫缩间歇子宫不完全放松","易出现胎窘","多见潜伏期延长","宫腔压力低"]
电压降落的纵分量主要受哪个因素影响?() ["无功","有功","频率","电流"]
什么是离子注入中常发生的沟道效应(Channeling)和临界角?怎样避免沟道效应?
暑湿病初起多()受邪。