1、Unit 2 Saving the EarthTopic 2 All these problems are very serious.Section C oxygen a special kind of oxygen called“ozone”(O3)a very big hole in the ozone layer,too much harmful radiation from the sun.In our daily life,we should face more environmental problems.Can you say something about them?放射，放射
2、物放射，放射物 n.洞，坑洞，坑CO2 carbon dioxide increase a lot,form a“blanket”,the heat from the sun cant escapeIn our daily life,we should face more environmental problems.Can you say something about them?v.出现，形成出现，形成n.种类，形式种类，形式二氧化碳二氧化碳毛毯，毯子毛毯，毯子渗出；逃渗出；逃跑；逃脱跑；逃脱 cause the level of the sea to rise called“the gr
3、eenhouse effect”or“globe warming”v.上升；起上升；起床；升起床；升起温室效应温室效应 millions of 无数无数 e.g.millions of reasons All over the world,people have cut down millions of trees.take away 拿走拿走 e.g.Take away the trash.Trees can stop the wind and water from taking the earth away.New wordscarbon dioxide:CO2oxygen:O2 e.g.
4、Trees can breathe in carbon dioxide and breathe out oxygen.blanket n.毛毯，毯子毛毯，毯子 e.g.The oxygen(O3)forms a“blanket”around the earth.escape n.&v.逃跑，逃脱逃跑，逃脱rise v.上升，上涨上升，上涨 e.g.The heat from the sun cant escape,so the temperature is rising.This is called“the greenhouse effect”.温室效应温室效应 level n.水平线，水平水
5、平线，水平 e.g.It causes the level of the sea to rise.Around the earth,theres a special kind of oxygen called“ozone”.（O3）ozone layer 臭氧层臭氧层Too much harmful radiation from the sun passes through the hole and reaches the earth.radiation n.放射，放射物放射，放射物What other kinds of environmental problems can you think
6、 of?Talk about them with your classmates.fewer treesfactory pollution1a Read and understand.Look at the following pictures and predict the main idea of the passage.All these problems are very serious.What can we do to solve them?traffic pollutionthe ozone layermore carbon dioxide The earth is 4.6 bi
7、llion years old.We humans have lived on the earth for only 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
8、 blows,the earth is taken away.Forests have become deserts,so many kinds of animals and plants are disappearing.Fewer Trees _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 the water.As a result,many rivers
9、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.Traffic PollutionFactory Pollution The Ozone Layer Too much harmful radiation from the sun pas
10、ses through the hole and reaches the earth directly.This is very dangerous because this kind of radiation can cause cancer._ 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 earth.The heat from the sun cant escape s
11、o the temperature is rising.More Carbon Dioxide 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.Read 1a again and choose the correct answers.1.Choose suitable titles
12、 for the Paragraphs 2-6,then write it down in front of each paragraph.A.Traffic pollution B.Factory pollution C.Fewer trees D.The ozone hole E.More carben dilxide2、What does our planet mean here?A.The sun.B.Mars.C.The moon.D.The earth.3、In the passage,“blanket”refers to _.A.carbon dioxide around the
13、 earth B.the ozone layer in the sky C.the forests around the world D.pollution all over the world4、The word it in the passage refers to _.A.CO2 B.O3 C.O2 D.H2O5、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 be
14、good for 对对有益有益 be good at 擅长擅长 e.g.Doing morning exercises is good for our health.Kangkang is good at swimming.while conj.而，然而而，然而 e.g.He is a worker,while I am a teacher.Language points as a result 结果结果 状语，用逗号隔开状语，用逗号隔开 e.g.As a result,he passed the test.the+比较级比较级+（名）（名）+（句子），（句子），the+比较级比较级+（名）（
15、名）+（句子）（句子）越越，越越 e.g.The more,the better.The more exercise you take,the healthier you will be.u people have cut down millions of trees.u the earth is taken away.uThe heat from the sun cant escape so the temperature is rising.uIt causes the level of the oceans to rise 1c Complete the notes according
16、to 1a.ProblemEffect on the environmentfewer trees forests become deserts,animals and plants disappeartraffic pollution cars and buses pollute air,health problemsProblemEffect on the environment pollute land and water,rivers and lakes deadfactory pollution harmful radiation reaches the earth,cause ca
17、ncer ozone hole ProblemEffect on the environment greenhouse effect,level of oceans rising,climate change.more CO2 2.Surf the Internet to collect more information about environmental problems and effects.Then discuss the information in groups and take notes.3.Combine the key points in 1c and 2 to for
18、m a short passage and pay attention to the proper linking words.As we all know,water pollution is becoming more and more serious.Some factories pour waste water into the rivers.As a result,it makes the water dirty and smell terrible.Most of fish in the water have died and we cant swim in the water.Y
19、ou can write it like this:Water is very important to human beings,so we should do our best to protect and save it.Luckily,our government is taking measures to protect the water from pollution.Exercise根据句意及首字母提示完成句子根据句意及首字母提示完成句子。A _ she had no time to travel,she still felt very happy this holiday.Th
20、e l_ of the sea is rising because of the green house effect.lthoughevel1.Summer is coming.The days are getting _.A.long and longB.long and longerC.more and more longD.longer and longer2._ trees are planted in our city every year.A.The millionsB.Millions ofC.Million ofD.MillionDBOzone is very importa
21、nt to the earth.O3:Written workDiscuss the meanings of the following expressions and then write down how they affect the environment.A special kind of oxygen called“ozone”The ozone layer can prevent the suns harmful radiation from reaching the earth.But now air pollution is destroying the ozone laye
22、r.This is very dangerous because this kind of radiation can cause cancer.CO2:the greenhouse effect:More and more carbon dioxide forms a“blanket”around the earth.Carbon dioxide.It mainly comes from burning oil,coal and wood.Carbon dioxide around the earth makes the temperature rise.The heat from the
23、sun cant escape so the temperature is rising.It causes the level of the oceans to rise and the climate of the earth to change.We learn:1.Some words:hole,form,rise 2.Some phrases:take away,refer to 3.Some sentences:All these problems are very serious,so we must do something now.We can:1.Talk about the harm of pollution.2.Combine the key points to form ashort passage.Homework1.Read 1a.2.Memorize the useful expressions and key words which we learn today.3.Finish Section C in your workbook.4.Review Section A-C and preview Section D.Goodbye!
