题目

下列反应所得溶液中一定只含有一种溶质的是 A．向稀硝酸中加入铁粉                    B．向稀盐酸中滴入少量的NaAlO2溶液C．向NaOH溶液中通入CO2气体       D．向MgSO4、H2SO4的混合溶液中加入过量的Ba(OH)2溶液  答案：D解析: () 13. Many beautiful are disappearing (消失)the serious pollution.   A. fish; because of   B. fishes; for   C. fish; because   D. fishes; as