当温度为70℃时,Cl2与NaOH溶液能同时发生两个自身氧化还原反应:Cl2+2NaOH═NaCl+NaClO+H2O,3Cl2+6NaOH═5NaCl+NaClO3+3H2O.若反应完全后测得溶液中NaClO与NaClO3的物质的量之比为4:1,则溶液中NaCl和NaClO的物质的量浓度之比为( )
A:11:2
B:9:4
C:1:1
D:5:1
I will never forget the song ________ she sang last night.