何为过电源保护？
参考答案：
当电路短路或电动机严重过载时，主电路自行释放起到作用。
Only when they were told the date of the wedding ________ their daughter would get married. [ ]
A. realized they
B. did they realized
C. did they realize
D. they did realize
处方调配差错性质可分为（）
A.无差错
B.差错未发生
C.内部核对控制
D.发给患者但未造成伤害
E.需要监测差错对患者的后果，并根据后果采取预防或减少伤害
