科普版九年级英语上册《Topic2AlltheseproblemsareveryseriousSectionC》优质课课件-16.ppt

1、Unit 2 Saving the EarthTopic 2 All these problems are very serious.Section C Discuss:1.All of the humans have a home.Its the _.2.Are all the things that we have done good for our planet?3.What have humans done to destroy our home?earth oxygenksdn a special kind of oxygen called“ozone”(O3)氧气氧气臭氧臭氧zn

2、ozone layer 臭氧层臭氧层zn le(r)1.Its like an umbrella of the earth and protects the earth.2.But What happens to the ozone layer(the umbrella)?There re some holes.Good or bad?Too much harmful radiation from the sun passes _ the hole and reaches the _ directly.throughearthcarbon dioxide(CO2)k(r)bn da:ksad

3、二氧化碳二氧化碳1.Carbon dioxide mainly comes from _,_ and _.burning oilcoalwood2.The heat from the sun cant escape（渗出）so the temperature is _.This is called“_.”risingthe greenhouse effectMore carbon dioxide around the earthNew words take away 拿走拿走 oxygen ksdn n.氧气氧气 hole hl n.洞，坑洞，坑 ozone layer zn le(r)臭氧层

4、臭氧层 radiation.redie()n n.放射，放射物放射，放射物 directly drek(t)li adv.直接地直接地 carbond dioxide k(r)bn da:ksad n.二氧化碳二氧化碳 form f:rm v.(使）出现；（使）形成使）出现；（使）形成 n.种类，形式种类，形式 blanket blkt n.毛毯，毯子毛毯，毯子 escape skep v.逃脱，渗出，逃跑逃脱，渗出，逃跑 rise raz v.上升，起床，升起上升，起床，升起 The green house effect 温室效应温室效应 referrf:(r)to v.提到，涉及，有关提到

5、，涉及，有关 fewer treesfactory pollutiontraffic pollutionthe ozone layermore carbon dioxideCan you match them?1a Read and understand.P40 1.Choose suitable tittles for Paragraphs 2-6.Then write it down in front of each paragraph.The earth is 4.6 billion years old.We humans have lived on the earth for only

6、 35 000 years,but during this period,we have changed our planet a lot in many ways.Some things weve 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

7、,so many kinds of animals and plants are disappearing.Fewer TreesA.Traffic pollution B.Factory pollution C.Fewer trees D.The ozone hole E.More carbon dioxide _ In big cities,cars and buses have polluted the air.Now many people in cities have health problems._Factories have also polluted the land and

8、 the water.As a result,many rivers and lakes are now dead._ Around the earth,theres a special kind of oxygen called“ozone”(O3).It is important to the earth.But now air pollution is destroying it and making a very big hole in the ozone layer.Too much harmful radiation from the sun passes through the

9、hole and reaches the earth directly.This is very dangerous because this kind of radiation can cause cancer.Traffic PollutionFactory Pollution The Ozone hole直接地直接地 _ Carbon dioxide(CO2)in the air has increased a lot.It mainly comes from burning oil,coal and wood.This has formed a blanket around the e

10、arth.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 Dioxide1.The age of the earth:_2.How

11、long have humans lived on earth?_3.Why are more and more sorts of animals and plants disappearing?_4._ and _ have polluted the air in big cities.5.Many rivers and lakes are _ because factories have polluted the land and the water.4.6 billion years oldFor only 35 000 years.Because forests have become

12、 deserts.CarsbusesdeadRead 1a again and finish.Write down only the key words when taking notes.1c Complete the notes according to 1a.ProblemEffect on the environmentfewer trees forests become deserts,animals and plants disappeartraffic pollution greenhouse effect,level of oceans rising,climate chang

13、ecars and buses pollute air,health problemspollute land and water,rivers and lakes deadharmful radiation reaches the earth,cause cancer factory pollution ozone hole more CO2P40 1b Read 1a and complete the following tasks.2.What does our planet mean here?A.The sun.B.Mars.C.The moon.D.The earth.We hum

14、ans have lived on the earth for only 35 000 years,but during this period we have changed our planet a lot in many ways.3.In the passage,“blanket”refers to _.A.carbon dioxide around the earth B.the ozone layer in the sky C.the forests around the world D.pollution all over the worldCarbon dioxide(CO2)

15、in the air has increased a lot.It mainly comes from burning oil,coal and wood.This has formed a“blanket”around the earth.P40 1b Read 1a and complete the following tasks.4.The word it in Paragraph 5 refers to _.A.CO2 B.O3 C.O2 D.H2OAround the earth,theres a special kind of oxygen called“ozone”(O3).It

16、 is important to the earth.But now air pollution is destroying it and that has made a very big hole in the ozone layer._P40 1b Read 1a and complete the following tasks.5.What is the best title for this passage?A.Environmental Problems B.Pollution on the Earth C.Hope for the Future D.The Greenhouse E

17、ffectP40 1b Read 1a and complete the following tasks.Group work:Discuss and write In our daily life,what should we do to protect the environment?请关注我们周围的环境污染情况，呼吁同学们保护环境,保护我们美丽的家园，生活中我们应该做到。Your passage may include：1.Problem2.Reason(原因）3.Harm or Effect4.Action(行动）We learn:1.Some words:hole,form,rise

18、 2.Some phrases:take away,refer to 3.Some sentences:All these problems are very serious,so wemust do something now.We can:1.Talk about the harm of pollution.2.Combine the key points to form a short passage.1.Read 1a.2.Memorize the useful expressions and key words which we learn today.3.Finish Sectio

19、n C in your workbook.4.Review Section A-C and preview Section D.1.The boy fell into the river,but luckily,he _ by the soldier.A.saved B.was savedC.has saved D.was saving2.Now some kinds of animals are becoming _.A.few and few B.fewer and fewerC.less and less D.more and more few单项选择。单项选择。BB3._ it was

20、 so cold,_ he went out without an overcoat.A.Although;but B.Although;/C.Although;so D.But;and4.People have cut down _ trees all over the world.A.million of B.millionsC.ten millions D.millions of5.Either my parents or my brother _ to see me.A.is coming B.are comingC.come D.have come BDAProject:Make a social survey.Then fill out the following table.And report to the classproblemReasonHarm or EffectActionsandstormsCut down millions of trees sandstormsChange rich land into desertDont cut down trees ozone hole