41. cover v. 覆盖 n. 封面

42. symbol n. 符号

43. flow v. 流淌

44. stream 小溪

Phrases:

1. turn that tap off 把水龙头关上

2. sound impatient 听起来不耐烦

3. a drop of water 一滴水

4. float comfortably 舒服地飘浮

5. enjoy the view 欣赏风景

6. the Yangtze River 扬子江

7. travel a long way 走了好长一段路

8. get cleaned up 变得彻底清洁

9. sound puzzled 听起来很困惑

10. a water treatment works 一个水加工厂

11. a thorough cleaning 一次彻底的清洗

12. a few chemicals 几种化学物质

13. chemistry lesson 化学课

14. a sewage plant 一个污水处理厂

15. in the first place 首先, (一开始的时候)

Unit 3 A dangerous servant

New words: