题目

已知NaCl、MgCl2、AlCl3三种溶液的物质的量浓度之比为1:2: 1，取等体积三种溶液分别与某浓度的AgNO3溶液恰好完全反应，则NaCl、MgCl2、AlCl3三种溶液消耗的AgNO3溶液的体积之比为                                                          （    ）     A．12:3:4      B．6:3:4       C．3:4:1        D．1:4:3 —Go and ask Mr. Green for help.  —But I don’t know ______. [     ]A. where does he liveB. where he livesC. where is he livingD. where he lived