The book, which is a useful guide for today's young people, deals with many questions and problems that face them at school and at home as well as in society.

A．are faced

B．confront

C．in opposition

D．meet

关于氢氧化钠滴定液（0.1mol/L）的配制与标定，不正确的是（）

A.应用减重法精密称取在105～110℃干燥至恒重的基准物邻苯二甲酸氢钾进行标定

B.应将NaOH先配制成饱和溶液，静置数日，取上清液配制

C.冷后贮于磨口棕色试剂瓶

D.标定时用酚酞作指示剂

E.应平行测定三次，根据消耗NaOH溶液的体积，计算NaOH标准溶液的浓度和平均浓度