80. We all don’t like the boy for his miser(吝啬), but he has the ______ actively to get near us because he has no little friends to play together with.

A．cheer

B．busy

C．face

D．Cheek

下列各组实验中，溶液的酸碱性没有明显变化的是（　　）

A．向氢氧化钠溶液中滴加硫酸镁溶液

B．向氯化钠溶液中滴加稀盐酸

C．向饱和氢氧化钠溶液中加入氢氧化钠固体

D．向硫酸中滴加氯化钡溶液