词汇运用。
1. Who is the _________ (close) person in your family?
2. I think it' s _________ (use) to talk with him. It's difficult to change his mind.
3. Did you have a nice time (ski) last week?
4. I'll never forget the __________ (beautiful) of the old houses.
5. Some subjects are _________ (bore). But I will try to learn them all.
6. They don't know how (solve) the problem.
7. We should take the _________ (follow) actions to help the wild animals.
8. He got ill yesterday. Today he feels even _________ (bad).
9. Our teachers told us that the earth (move) around the sun.
10. _________ (wolf) eat smaller animals when they are hungry.
和平均自由程
的变化情况是（）。