1. You'd better let in some fresh _____ (空气).
2. Sue always _____ (分享) things with her friends.
3. There is a long _____ (历史) behind that building.
4. A little knowledge is a _____ (危险的) thing.
5. Simon lives on the _____ (第九) floor.
6. The rain has stopped ______（完全地).
7. Eric is so _____ (有礼貌的)! He holds the door open for others.
8. Sandy has lots of _____ (业余爱好).
9. They _____ (聊天) until Amy came up the stairs.
10. She has a problem and she wants to know how to _____ (解决) it.