Chapter 18 SBII Units 13-14

　☆重点句型☆

1. Life in the oceans range from the tiniest plants all the

way up to giants like sharks and whales.

2. Water is actually quite simple, but the way the water

molecule is formed gives water its unique properties.

3. They form a polar molecule, that is, one with a slightly

positive end and a slightly negative end.

4. The salinity of the earth's oceans is about thirty-five

parts per thousand, meaning that there are about 35

grammes of dissolved solids and gases in one kilo of

water.

5. Heat capacity is the amount of energy it takes to raise

the temperature of a substance by one degree

centigrade.

6. Water, which seems ,so simple and common, is what

makes life possible.

7. Freedom fighters can be found everywhere and they are

of all times.

8. From the late eighteenth century to well into the

nineteenth century different people struggled for their

rights.

☆重点词汇☆

1. sailor n. 水手

2. transport n. & vt. 运输

3. range vi.& n. 变动

4. hydrogen n. 氢

5. oxygen n. 氧气

6. relative adj. 相对的

7. solid n. 固体

8. freezing adj. 冰冻的

9. pure adj. 纯净的

10. relationship n. 关系

11. float v. 漂浮

12. decrease vi. 变小

13. centigrade adj. 摄氏温度的

14. absorb vt. 吸收

15. stable adj. 稳定的

16. steady adj. 平稳的

17. trust vt. 信任

18. nursery n. 保育院

19. freedom n. 自由

20. civil adj. 国内的，公民的