高中英语 unit13 The Water Planit课件 新人教

1、2021/8/11 星期三1Why is it blue? Water PlanetWhat can water be used for? 2021/8/11 星期三2drinkWash clothes2021/8/11 星期三3irrigationtransport2021/8/11 星期三4provide living space for marine life2021/8/11 星期三5They are floating on the surface of Dead Sea. Can you explain how they can do this?entertainment2021/8

2、/11 星期三6propertiesWhat properties or characteristics do you know about water?colorlesstastelessodorlessthree formsfeeling wetabsorbing heatdissolving2021/8/11 星期三71.What else have you learned about water and the water planet?3.Do you know any properties of water?2.What would happen if there were no

3、water on our planet?2021/8/11 星期三8Activity 1. Structure of the passage 1 minute to skim the passage and fill in the chart below. You do not need to read the whole text. The properties of waterchemical structure salinity densityheat capacityocean motion2021/8/11 星期三9 Careful Reading 2021/8/11 星期三10_p

4、ercent of the living space on earth is in the oceans.There are about _ species in the oceans.Marine life is incredibly rich and varied. Paragraph 1Ninety-ninefive million海洋生物数量之大，种类之多，简直难以置信2021/8/11 星期三11Life in the oceans ranges from the tiniest plankton all the way up to giants like sharks and wh

5、ales. range fromto / range between and _从到.之间变化_ N: 范围，射程a wide range of interests and hobbiesWhat is the range of the gun?海洋里的生物从微小的浮游生物到巨大动物，如鲨鱼和鲸鱼，都无所不包。2021/8/11 星期三12Normal state of water: solid liquid gas negative end: + positive end: + polar: + medium: average channel means conditionH2O: 2_ +

6、 1_ = 1_Hydrogen AtomsOxygen AtomH2O MoleculeParagraph 22021/8/11 星期三13Waters unique chemical structure Oxygen AtomHydrogen Atoma polar (adj.极性的)molecule2021/8/11 星期三14But the way the water molecule is formed gives water its unique properties但是水分子的结构方式赋予了水独特的性质。Because water is polar, it can break b

7、oth solids and gases.因为水是极性的，所以它能够分解固体和气体。The nutrients in whatever falls into the ocean quickly become available to other living creatures.任何落入海洋的东西其所含的营养物质都能很快被其他生物所利用。（宾语从句）2021/8/11 星期三15 sea water (salt water) =_+ _+_ salinity of sea water affects: _and_Salt water has a _freezing point and is _

8、than pure water.salinity of sea water: 35 35% dissolved gasesdissolved solidspure waterweightfreezing pointparagraph 3lowerheavier2021/8/11 星期三16 the pure water is what gives sea water its main properties，是纯水赋予了海水的主要特征The salinity of the earths oceans is about thirty-five parts per thousand, meaning

9、 that there are about thirty-five grammes of dissolved solids and Gases in one kilogramme of water. 地球海洋里的盐度约为35%0， 即在每千克的水中约含有35克溶解的固体和气体Which means that（表语从句）2021/8/11 星期三17Factors of density: _and _Unit of density: _ = _Density of pure water: _=_massvolumekg/m3kilogrammes per cubic metre1,000 kg/

10、m3one cubic metre of water weighsParagraph 4one thousand kilogrammes2021/8/11 星期三18Density is the relationship between mass and volume and is measured in Kilogrammes per cubic metre .密度是指质量与容量的关系，其测量单位是每立方米的公斤数If a substance has a higher density, say 5,000kg/m3Marine animals and plants take advantag

11、e of the density of water.2021/8/11 星期三19With the right kind of body, it is possible to float around in the ocean, and let the water do the work.When water freezes, its density decreases. If it did not, the oceans would be frozen solid. 当水结冰时，它的密度就减小。如果密度不减小，整个海洋就会冻结成固体。如果体型结构适宜的话，他们可以在水中四处游动，而这项任务则

12、是由海水来完成的2021/8/11 星期三20Opposite meaning of absorb: give off change create Heat capacity: water temperature su substance energy Paragraph 52021/8/11 星期三21Heat capacity is the amount of energy it takes to raise the temperature of a substance by one degree centigrade.Water can absorb and give off a lot

13、 of heat without big changes in temperature,热容量是将一种物质的温度升高一度所需要的能量水可以吸收或放出大量的热量而其温度不会有很大变化2021/8/11 星期三22be sensitive to large or sudden changes in temperature（动植物的）生活环境，栖息地The water in the oceans also keeps the temperature of the earth steady by absorbing and giving off heat.对敏感/过敏habitat：海水通过吸收和释放

14、热量来使地球的温度保持稳定2021/8/11 星期三23 Paragraph 7 Main idea: significance of water Paragraph 6How does the water in the ocean move?Dense water sinks and less dense water is pushed to the surface.2021/8/11 星期三24This circulation adds energy to the marine ecosystems and moves nutrients aroundWater ,which seems

15、so simple and common, is what makes life possible. The most important thing we can learn about water, however, is that we must protect it and use it wisely.这种循环给海洋生态系统增加了能量，并使营养物质向四周移动水，看似简单而平凡，却是它使生命成为可能。然而对水我们所了解的最重要的是：我们必须保护它，合理利用它。（非限制性定语从句）（表语从句）（定语从句）（表语从句）2021/8/11 星期三25Water is a liquid at room temperature.The reason why water can break down other substances on earth is that water has high heat capacity.Like all the other substances, water gets smaller (contract 缩小) when it freezes.Pure water has a higher freezing point and lighter than salt water.The salinity of the earths oceans