27.释放出大量的热　　 give off a lot of heat

26.把温度提高1℃ raise the temperature by one degree centigrade

25.能量　　　 the amount of energy

24.利用水的密度

take advantage of the density of water

23.每立米用公斤来衡量

be measured in kilograms per cubic metre

22.一球上大洋的含盐量

the salinity of the earth’s oceans

21.与纯水混合 mix with pure water

20.有一个相对高的结冰点

have a relatively high freezing point

19.水在室温下是液体

water is a liquid at room temperature

18.为其他生物所利用become available to

　other living creatures