题干
看图，读一读，将字母的序号写在横线上。
A. In winter, it is cold. The ugly duckling has no home. He is very sad.
B. Uncle Lin has a garden. There are many plants in it. He waters them every day.
C. We are three little pigs. We are clever. We are not afraid of the big bad wolf.
D. Mother Duck has some eggs. She sits on the eggs.
2B（g）+ C（g），若反应物浓度由0.1mol·L－1降到0.06mol·L－1需20s，那么由0.06 mol·L－1降到0.024 mol·L－1，需要反应的时间是（ ）
