英语：unit 4 《global warming 》教案reading(新人教版选修6).pptx

1、英语：Unit 4 Global Warming 教案-reading（新人教版选修,6）,Period 2 Pre-reading, Reading, Comprehending,Teaching Goals:,1.To read about global warming.,2.To get someidea about theeffect of global warming.,3.To develop somebasic reading skills.,Teaching Procedures:,Step 1. Warming Up,Purpose: To arouseSs interest

2、 in learning about global warming.,1. Team work,Answer the questions below:,(1) Have you ever seen a greenhouse?,(2) How does agreenhouse work?,(3) What do you think greenhousegases do?,2. Group work,Look at thepicture, and ask Ss somequestions.,T: What is this building madeof?,S1: Its madeof plasti

3、c. T: Whats its purpose?,S2: Plants can grow in it when its cold outside.,T: How does it work?,S3: Theglass traps theheat from thesun, making the air warm so that plants grow better.,Step 2. Pre-reading,Purpose: To get Ss to learn about greenhousegases.,1. Group work,Now look at theword “GREENHOUSE

4、GASES”. What does it mean?,Greenhouse gases (GHG) are gaseous components of the atmosphere that,contribute to the greenhouse effect .The major natural greenhouse gases are,water vapor, which causes about 36-70% of the greenhouse effect on Earth,(not including clouds): carbon dioxide, which causes be

5、tween 9-26%; and,ozone, which causes between 3-7%(note that it is not really possible to,assert that such-and-such a gas causes acertain percentage of the GHE, because the influences of the,various gases are not additive .The higher ends of the ranges quoted are for the gas alone ;the lower,end ,for

6、 thegas counting overlaps).,Naturally occurring greenhousegases include water vapor, carbon dioxide, methane, nitrous,oxide, and ozone. Certain human activities, however, add to the levels of most of these naturally,occurring gases.,Very powerfulgreenhousegases that arenot naturally occurring includ

7、e hydrofluorocarbons,(HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6), which aregenerated in a,variety of industrial processes.,Each greenhouse gas differs in its ability to absorb heat in theatmosphere. HFCs and PFCs,are themost heat-absorbent.,2. Individual work,Get Ss to answer thes

8、equestions individually. Then let them discuss theanswers.,(1) Who wrotethemagazine article? What is thename of the magazine?,(2) What are the names of the threescientists mentioned in the article?,(3) What do they think about global warming?Do they agree with one another?,(4) What are the two graph

9、s about?,(5) What is the main topic of the article?,Step 3. Reading,1. Skimming,Purpose: To get abrief understanding of the text.,Read through the text, preferably the first and the last sentences of each paragraph and,write the key sentence of each paragraph.,Key sentences of each paragraph:,(1) A

10、debate over whether it is human activity that has caused the global warming or whether it is just a,natural phenomenon.,(2) Many scientists believe people have caused theincreasein theearths temperature.,(3) The increased extra amount of carbon dioxide traps more heat energy causing the global tempe

11、rature,to go up.,(4) Thelevels of carbon dioxide have increased greatly over the last 100 to 150 years.,(5) Therearesomedifferent attitudes towards thecauses of this increasein carbon dioxide.,(6) Over the next 100 years the amount of warming could be as low as 1 to 1.5 degrees Celsius but it could

12、beas much as 5 degrees Celsius. (7)An increaseof five degrees would be a catastrophe. (8) Futurewarming would causethesealevel to rise by several meters. (9) Somepredict any warming will be mild with few bad environmental consequences. (10) More carbon dioxide is apositive thing. (11) No one knows w

13、hat theeffects of globalwarming will be. 2. Scanning Purpose: To get Ss to have somedetails in the text. Read the article carefully. Are these statements trueor false? Write a T for each truesentence and an F for each false sentence.,(1) Thetemperaturelast century didnt increase much. (,),(2) Everyo

14、ne believes that global warming is caused by theactivities of humans.,(,),(3) JaniceFoster believes that burning fossil fuels causes global warming. (,),(4) Natural gas is a greenhousegas.,( ),(5) Carbon dioxide is a byproduct of burning fossil fuels. (,),(6) People accept Charles Keeling s data bec

15、ausehetook accurate measurements. ( ),(7) Flooding could beone of the effects of futureglobal warming. (,),(8) GeorgeHambley believes scientists arejust guessing about theeffects of global warming.( ),( ),(9) Geroge Hambley is worried about the effects of carbon dioxideon plant growth. (10) It is cl

16、ear what the effects of global warming will be. Suggested Answers: (1) F (2) F (3) T (4) F (5) T (6) T (7) T (8) T (9) F (10) F 3. Listening Purpose: To train Ss listening ability. Listen to the tapeand follow it in a low voice.,4. Group work Ss aredivided into four groups. Each group is supposed to

17、 read through each part and then discuss them. Part 1 (Paragraph 1) (1) compare 比较 常见用法： comparewith 把和比较 Compared with him, I am fast. compareto 把比作 Life is often compared to voyage. (2) comeabout 发生 How did it comeabout? 那事是怎么发生的? 常见词组：,comeacross,偶遇；碰到,comeround,恢复知觉，,cometo cometo oneself,涉及；到达；

18、共计 恢复知觉,comealong comeout comeup with (4) phenomenon,进展；进行 公开；问世；出版 想出 n 现象,It is only a social phenomenon, but not a phenomenon of nature. Part 2 (Paragraph 2, 3, 4) (1) fuel n 燃料 Dont leave the engine switched on .It wastes fuel. 拓展：fuel v 加油；补给燃料 Thecar is being fuelled ready to try to beat the s

19、peed record. (2) quantities of 大量 Large quantities of money have been spent on the bridge., 拓展： a large quantity of 大量的,He ate alarge quantity of nice.,(3) per prep 每; 每一,Thefruit costs 30 penceper kilo.,How much do you earn per week?,Part 3 (Paragraph 5,6,7,8,9),(1) data n 资料; 数据,We havent got enou

20、gh data.,(2) result in 导致,Theaccident resulted in thedeath of two passengers.,It resulted in success., 拓展：result from 由于,His illness resulted from eating bad food.,(3) catastrophen 突如其来的大灾难；大灾祸,Thewar was aterrible catastrophein which many people died.,(4) climate n 气候,We have amild climate here.,(5

21、) consequence n 结果；后果；影响,As a consequenceof being in hospital, Shelly decided that shewanted to becomea nurse., 常见词组：in consequence 因此，由此,in consequenceof由于的缘故,(6) statevt 陈述；说明,The busmen have stated that the strike will continue until general agreement is reached about pay and,working conditions.,

22、(7) range n he just kept on., 拓展：,keep on doing 与 keep doing 的区别：,keep on doing 表示动作反复发生；keep doing 表示状态或动作的持续。,He kept on standing up in class. 他在课堂上一再地站起来。,He kept standing there for half an hour without moving.他一动不动地在那里站了半个小时。,Step 4. Post-reading,Purpose: To have a deep understanding of the text

23、.,1. Group work,Now you are going to discuss thestatement:We should do nothing about global warming.,Follow theseinstructions:,(1) Get into groups of six. Decide which three in your group are going to agree with the statement,(GroupA) and which threeare going to disagree with the statement (Group B)

24、.,(2) Group A students discuss why they agree with the statement; Group B students discuss why they,disagree.,(3) Groups A and B get together. They tell each other the reasons for agreeing or disagreeing with the,statement.,2. Individual work,Ask Ss to answer thefollowing questions. Present their op

25、inions to other classmates.,(1) What do you think of global warming?,(2) Do you think it serious?,3. Discussion,(1) Global warming refers to an average increase in the earths temperature, which in turn causes changes,in climate.,(2) Earths climate has been changing constantly over its 5-billion-year

26、 history.,(3) Theearth could be getting warmer on its own.,(4) Scientists are sure about the greenhouse effect. They know that greenhouse gases make the Earth,warmer by trapping energy in theatmosphere.,(5) Without the greenhouseeffect, theearth would not be warm enough for humans to live.,(6) A warmer earth may lead to changes in rainfall patterns, a rise in sea level, and a wide range of,impacts on plants, wildlife, and humans.,(7) Scientists dont know exactly what will happen in the future. But they can use special computer,prog