A.FeCl3 B.BaCl2 C.NaCl+Na2S D.NaCl+Na2SO4
A.稀NH4NO3溶液B.稀HCl溶液C.純水D.稀HNO3溶液
A.10-4.7 B.10-3.9 C.10-2.7 D.10-3.0