题干
—Hi, Tracy, you look tired.
—I am tired. I the living room all day.
—I am tired. I the living room all day.
A：painted
B：had painted
C：have been painting
D：have painted
答案(点此获取答案解析）
C
bB（g）达到平衡后，保持温度不变，将容器体积增大一倍，当达到新的平衡时，B的浓度是原来的60%，则：
