A:NH4++H2O⇌NH3•H2O+H+
B:Fe3++3H2O═Fe(OH)3↓+3H+
C:S2﹣+2H2O═H2S+2OH﹣
D:Br﹣+H2O═HBr+OH﹣
如图为自然界碳、水物质循环示意图.读图回答下题.