单项选择题
A.100g/LB.120g/LC.200g/L
A.NiSO4•5H2OB.NiSO4•4H2OC.NiSO4•6H2OD.NiSO4•7H2O
A.碳酸钴溶液B.硫酸钴溶液C.氯化钴溶液