题目

 将固体NH4I置于密闭容器中，在一定温度下发生下列反应：①NH4I(s)NH3(g)＋HI(g)；②2HI(g)H2(g)＋I2(g)。达到平衡时，c(H2)＝0.5mol·L－1，c(HI)＝4mol·L－1，则此温度下反应①的平衡常数为(    )A．9             B .    16       C．20           D．25  答案： D Her son__________coffee, but now he _______milkA. is used to drink; is drinkingB. used to drinking; drinksC. is used to drinking; used to drinkD. used to drink; is used to drinking