题目

已知某温度下，0.1mol/LNaHA的强电解质溶液中，c(H+)<c(OH-)，则下列关系或说法一定错误的是（ ） A . c(Na+)=c(HA-)+2c(A2-)+c(OH-) B . c(H2A)+c(HA-)+c(A2-)=0.1mol/L C . 无法确定水的离子积常数 D . c(A2-)+c(OH-)=c(H+)+c(H2A) 答案：A从方框中选择正确的句子补全对话。A: What’s wrong with you, Helen?B:    小题1:    I have a cold.A: Bad luck!   小题2: B: Oh, but I’m busy now and I must finish these exercises in the class.A:  小题3:   He will ask you tohave a rest at home.B:    小题4:   I don’t want to ask for leave.A:   小题5:  You’d better lie down and have a good rest now.B: OK. I’ll ask for leave at once. Thank you very much.