题目

下列各组离子中，一定能大量共存的是 （      ）          A．加入铝粉只有氢气产生的溶液中：Na+、SO42-、NO3-、Mg2+、     B．滴加石蕊试液显红色的溶液中：Fe3+、NH4+、Cl-、SCN-     C．在0.1mol/L的NaHSO4溶液中：NH4+、Na+、Al3+、Cu2+、NO3-     D．在0.1mol/L的ＮaHCO3溶液中K+、Al3+、Fe3+、NO3- 答案：C 解析: 略“________.” “It' s ninety dollars.” [　　] A．How much is it?B．How is it? C．How many is it?D．How much are they?