题干
On Christmas Day, children have __ ___ singing, dancing and playing games.
A：fu
B：a fu
C：the fu
D：fu
答案(点此获取答案解析）
D
Ba2＋(aq)＋SO(aq)的平衡常数KSP＝c(Ba2＋)·c(SO )，称为溶度积常数。