【简答题】邻苯二甲酸氢钾在酸碱滴定中用作标定NaOH溶液的基准物质,在非水滴定中却用作标定HClO 4 溶液的基准物质,两者矛盾吗?写出各自标定的化学反应方程式和浓度计算公式?
【简答题】如图,下列条件不能判定△ABC≌△EDF的是( ) A.AB=ED,AC=EF,BC=DF B.AC=EF,BC=DF,∠C=∠F C.AB=ED,∠C=∠F,∠A=∠E D.AB=ED,BC=DF,∠C=∠F
【判断题】Milling
machines are the principal machine tool which is used in turning.
【简答题】My friend a fter my cat while I was on holiday.