I shall never forget those days ______ I spent with the earthquake victims(受害者), _____ has a great effect on my life.

A．that; which

B．when; that

C．which; that

D．when; who

N_A表示阿伏加德罗常数，下列说法中正确的是  [ ]

A．3.6 g重水中所含质子数为2N_A         

B．标准状况下，2.24LSO₃含有的分子数为0.1N_A 

C．1 L 0.5 mol/L的(NH₄)₂SO₄溶液中含有N_A个NH₄⁺

D．1 molMg与足量O₂反应生成MgO失去2N_A个电子