题干
---______ have you been in class today? ---For two hours.
A：How often
B：How long
C：How many
D：How soon
答案(点此获取答案解析）
B
---______ have you been in class today? ---For two hours.
A：How often
B：How long
C：How many
D：How soon
bB(g)达平衡后，保持温度不变，将容器体积增加一倍，当达到新的平衡时，B的浓度是原来的60%，则下列说法不正确的是( ).
