下列离子方程式书写正确的是 A.AlCl3溶液与过量的浓氨水:Al3++4NH3·H2O=AlO2-+4NH4++2H2O B.向Ca(ClO)2溶液通入过量的CO2:Ca2++2ClO-+CO2+H2O=CaCO3↓+2HClO C.FeSO4酸性溶液暴露在空气中:4Fe2++O2+4H+=4 Fe3++2H2O D.CuSO4溶液与少量的Ba(OH)2溶液:Ba2++SO42-=BaSO4↓ 答案:CIt takes time to go to Chengdu by plane than by train. A. more B. fewer C. longer D. less