九上U2T2SC.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,Unit,2,Sav,ing,the,Earth,Topic2 All these problems are very serious.,Section C,孟津县直中学英语组,oxygen,a special kind of oxygen,called“ozone”(O,3,),a very big hole in the ozone layer,too much harmful radiation from the sun,CO,2,carbon dioxide,increase a lot,form a“blanket”,the heat from the sun cant escape,cause the level of the sea to rise,called“the greenhouse effect”,or“globe warming”,fewer trees,factory pollution,traffic pollution,the ozone layer,more carbon dioxide,Can you match them?,Read and understand,（影片）,Can you choose a suitable title for each paragraph from the phrases below?,The earth is 4 600 million years old.We humans have lived on earth for only 35 000 years,but during this period we have changed,our planet,a lot in many ways.Some things we,ve done are very good for the earth while some are bad.,_,All over the world,people have cut down millions of trees.When it rains or when the wind blows,the earth is taken away.Forests have,become deserts,so more and more sorts of animals and plants are disappearing.,Fewer Trees,_,In big cities,cars and buses have polluted the air.Many people in cities now have health problems.,_,Factories have also polluted the land and the water.As a result,many rivers and lakes are now dead.,_,Around the earth,theres a special kind of oxygen called“ozone”(,O,3,).It is important to the earth.But now air pollution is destroying,it,and that has made a very big hole in the ozone layer.Too much harmful radiation from the sun passes through the hole and reaches the earth directly.This is very dangerous because this kind of radiation can cause cancer.,Traffic Pollution,Factory Pollution,The Ozone Layer,_,Carbon dioxide(CO,2,)in the air has increased a lot.It mainly comes from burning oil,coal and wood.This has formed a“,blanket,”around the earth.The heat from the sun cant escape so the temperature is rising.This is called“the greenhouse effect”.It causes the level of the oceans to rise and the climate of the earth to change.,All these problems are very serious,so we must do something now.,More Carbon Dioxide,Read 1a again and choose the best answers.,1,、,What does,our planet,mean here?,A.The sun,.,B.Mars,.,C.The moon,.,D.The earth,.,Read 1a again and choose the best answers.,2,、,Which is,NOT,true?,A.Cars can pollute the air.,B.Factories can pollute the water.,C,.The fewer trees,the better.,D,.Not all the things we have done are good for the earth.,3,、,The word,it,in the passage refers to _.,A.CO,2,B.O,3,C.O,2,D.H,2,O,Read 1a again and choose the best answers.,4,、,In the passage,“,blanket,”,refers to,_.,A.carbon dioxide around the earth,B.the ozone layer in the sky,C.the forest,s,around the world,D.pollution all over the world,5,、,The level of the,oceans,is rising because of _.,A.pollution,B.few trees,C.the greenhouse effect D.changes in the climate,Read 1a again and choose the best answers.,6,、,What is the best title for this passage?,A.Environmental Problems,B.Pollution on the Earth,C.Hope for the Future,D.The Greenhouse Effect,Read again and pay attention to the phrases,1.cut down,2.,millions of,3.,take away.4.as a result,5.The earth,is taken away,.,6.Too much harmful radiation from the sun,passes,through,the hole.,7.The heat from the sun cant escape so the,temperature,is rising.,8.It,causes,the level of the oceans,to rise,Exercises,：,用所给词的适当形式填空,(cut)down too many trees is harmful to human beings,animals and plants.,2.The sun,(rise)in the east.,3.Do you know that the Earth is home to,(million)of animals?,4.Do you know who _(take)away my umbrella?,5.Noise pollution can cause people _(become)sick or deaf.,CO2:,Ozone is very important to the earth.,O,3,:,Homework,Discuss the meanings of the following expressions and then write down how they affect the environment.,the greenhouse effect:,More and more carbon dioxide forms a“blanket”around the earth,.,Bye-bye!,