题干
— Good evening, Cindy.
— , Helen.
A：Good morning
B：Good afternoon
C：Good evening
答案(点此获取答案解析）
C
— Good evening, Cindy.
— , Helen.
A：Good morning
B：Good afternoon
C：Good evening
2PbSO4+2H2O则下列说法正确的是（ ）
