A:氢氧化钠溶液中加入少量碳酸氢钙溶液: Ca2++HCO3-+OH-=CaCO3↓+H2O
B:氯气和水反应:Cl2+H2O===2H++Cl-+Cl-+ClO-
C:二氧化硅与烧碱溶液反应:SiO2 +2OH- ='==' SiO32-+H2O
D:氯化铝溶液中加入过量氨水:Al3++4NH3·H2O=AlO2-+4NH4++2H2O
Please translate the sentence _______ Chinese. I can't understand it.