— He still drinks a lot and often gets drunk, do you know that?

— Yes. But I don't know how I can ____ him to give up. [ ]

A. suggest

B. ask

C. persuade

D. say

用来标定EDTA溶液的基准物应为（）。

A、草酸；

B、碳酸钠；

C、氧化锌；

D、盐酸。