A:闭合K1,断开K2,可防止Fe发生吸氧腐蚀
B:闭合K1,断开K2,Cl﹣向石墨电极移动
C:闭合K2,断开K1,可用于制备家用消毒液(主要成分NaClO)
D:闭合K2,断开K1,电解质溶液中Na+的浓度不变
He lives _______, but he never feels _______, because he likes reading.