厚朴的净制方法为() ["A.去残茎","B.去残根","C.去皮壳","D.去毛","E.去心"]
已知同步电动机额定容量为7.5MVA,超瞬态电抗百分值x″%=20,额定电压为10kV,则在基准容量为Sj=100MVA下的电抗标幺值为()。 ["0.20","3.33","0.267","2.667"]
测定二价铁时,磁铁样品应在()气体保护下溶解于盐酸。 ["氮","二氧化碳","一氧化碳","氢"]
已知变压器额定容量为4MVA,阻抗电压百分值uK2%=5.5,电压为10.5/6.3kV,则在基准容量为Sj=100MVA下的电抗标幺值为()。 ["1.5","1.75","1.375","2.0"]
患者女性,25岁。孕1产0,孕37周,既往有风湿性心脏病病史,诉轻微活动后感觉胸闷、气急,休息时无不适。产科检查:LOA,胎心142次/分,有不规则宫缩。该患者心功能分级为() ["Ⅰ级","Ⅱ级","Ⅲ级","Ⅳ级","Ⅴ级"]
丈量两段距离,一段往返测为126.78m,126.68m,另一段往返测为357.23m,357.33m,两段距离丈量的结果各为多少?试问哪一段量得精确?