一、根据首字母或中文提示填写单词（每小题1分，共20分）
1. Now many people like keeping p_______, such as dogs, cats and birds.
2. It is polite to k_______ on the door before going in.
3. We can't f_______ the animals when we visit the zoo.
4．Birds have f_______ and wings(翅膀)．
5. I usually c_______ a bus to school.
6. -What's the t_______ with your bike? -It doesn't work well.
7. Mum, I think you should not buy clothes made of animal f_______.
8. This room is too n_______, and I can't sleep well.
9. We'd better b_______ our teeth twice a day.
10. There is only one bridge over the river. People will b_______ another one soon.
11. Is it_______（必要的）for every Chinese s
