下列离子方程式书写正确的是( )
A:标准状况下2.24L CO2通入1 mol·L-1100mL氢氧化钠溶液中:CO2 + OH-= HCO3-
B:硝酸铝溶液中加入过量氨水:Al3-+ 4NH3·H2O = AlO2- + 4 NH4+ + 2H2O
C:Na2S水解: S2-+ 2 H2O H2S + 2OH-
D:等物质的量的NH4HCO3与NaOH在溶液中反应:HCO3- +NH4++ OH- =CO32- +NH3·H2O
文字简练单纯,不加渲染烘托,这种写作手法就是白描。请赏析本文所用的白描手法。
I couldn't walk when I_______ a baby. ( )
-----I'm waiting for the mail. Do you know it will arrive?
-----Usually it comes by 4:00 p.m.