1、英语：Unit4Global warmingReading教案（2）（新人教版选修6）Pre-reading, Reading, Comprehending Teaching Goals:1.To read about global warming.2.To get some idea about the effect of global warming.3.To develop some basic reading skills.Teaching Procedures:Step 1. Warming UpPurpose: To arouse Ss interest in learning a
2、bout global warming.1. Team workAnswer the questions below:(1) Have you ever seen a greenhouse?(2) How does a greenhouse work?(3) What do you think greenhouse gases do?2. Group work Look at the picture, and ask Ss some questions.T: What is this building made of? S1: Its made of plastic.T: Whats its
3、purpose?S2: Plants can grow in it when its cold outside.T: How does it work?S3: The glass traps the heat from the sun, making the air warm so that plants grow better.Step 2. Pre-readingPurpose: To get Ss to learn about greenhouse gases.1. Group workNow look at the word “GREENHOUSE GASES”. What does
4、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 between 9-26%; and oz
5、one, which causes between 3-7%(note that it is not really possible to assert that such-and-such a gas causes a certain 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 the gas counting
6、overlaps).Naturally occurring greenhouse gases include water vapor, carbon dioxide, methane, nitrousoxide, and ozone. Certain human activities, however, add to the levels of most of these naturally occurring gases.Very powerful greenhouse gases that are not naturally occurring include hydrofluorocar
7、bons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6), which are generated in a variety of industrial processes.Each greenhouse gas differs in its ability to absorb heat in the atmosphere. HFCs and PFCsare the most heat-absorbent.2. Individual workGet Ss to answer these questions indiv
8、idually. Then let them discuss the answers.(1) Who wrote the magazine article? What is the name of the magazine?(2) What are the names of the three scientists mentioned in the article?(3) What do they think about global warming? Do they agree with one another?(4) What are the two graphs about?(5) Wh
9、at is the main topic of the article?Step 3. Reading1. SkimmingPurpose: To get a brief 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 debate over whether
10、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 the increase in the earths temperature.(3) The increased extra amount of carbon dioxide traps more heat energy causing the global temperature to go up.(4)
11、 The levels of carbon dioxide have increased greatly over the last 100 to 150 years.(5) There are some different attitudes towards the causes of this increase in 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 be as much as 5
12、degrees Celsius.(7) An increase of five degrees would be a catastrophe.(8) Future warming would cause the sea level to rise by several meters.(9) Some predict any warming will be mild with few bad environmental consequences.(10) More carbon dioxide is a positive thing.(11) No one knows what the effe
13、cts of global warming will be.2. ScanningPurpose: To get Ss to have some details in the text.Read the article carefully. Are these statements true or false? Write a T for each true sentence and an F for each false sentence.(1) The temperature last century didnt increase much. ( )(2) Everyone believe
14、s that global warming is caused by the activities of humans. ( )(3) Janice Foster believes that burning fossil fuels causes global warming. ( )(4) Natural gas is a greenhouse gas. ( )(5) Carbon dioxide is a byproduct of burning fossil fuels. ( )(6) People accept Charles Keeling s data because he too
15、k accurate measurements. ( )(7) Flooding could be one of the effects of future global warming. ( )(8) George Hambley believes scientists are just guessing about the effects of global warming.( )(9) Geroge Hambley is worried about the effects of carbon dioxide on plant growth. ( )(10) It is clear wha
16、t 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) F3. ListeningPurpose: To train Ss listening ability.Listen to the tape and follow it in a low voice.4. Group workSs are divided into four groups. Each group is supposed to read throug
17、h each part and then discuss them. Part 1 (Paragraph 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) come about发生How did it come about? 那事是怎么发生的? 常见词组：come across偶遇；碰到come round恢复知觉，come along进展；进行come to涉及；到达；共计come out公开；问世；出版come
18、to oneself恢复知觉come up with想出(4) phenomenon n 现象It is only a social phenomenon, but not a phenomenon of nature. Part 2 (Paragraph 2, 3, 4)fuel n 燃料Dont leave the engine switched on .It wastes fuel. 拓展：fuel v 加油；补给燃料The car is being fuelled ready to try to beat the speed record.(2) quantities of大量Larg
19、e quantities of money have been spent on the bridge. 拓展： a large quantity of大量的He ate a large quantity of nice.(3) per prep 每; 每一The fruit costs 30 pence per 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 enough data.(2) result in导致The accident resulte
20、d in the death of two passengers.It resulted in success. 拓展：result from 由于His illness resulted from eating bad food.(3) catastrophe n 突如其来的大灾难；大灾祸The war was a terrible catastrophe in which many people died.(4) climate n 气候We have a mild climate here. (5) consequence n 结果；后果；影响As a consequence of be
21、ing in hospital, Shelly decided that she wanted to become a nurse. 常见词组：in consequence 因此，由此in consequence of由于的缘故(6) state vt 陈述；说明The busmen have stated that the strike will continue until general agreement is reached about pay and working conditions.(7) range n & v 种类；范围；幅度There is a wide range o
22、f temperature.气温变化很大。 vi (在一定范围内)变化The number ranges between 5 and 15. vt 排列，整理Please range the goods neatly in the shop window. Part 4 (Paragraph 10)(1) build up逐步建立；增加；增进We need to build up our reputation.Traffic is building up on roads into the city.(2) Keep on 继续 Price kept on increasing. He did
23、nt stop running; 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-readingPurpose: To have a deep understanding of the text.1. Gro
24、up workNow you are going to discuss the statement: We should do nothing about global warming. Follow these instructions:Get into groups of six. Decide which three in your group are going to agree with the statement (Group A) and which three are going to disagree with the statement (Group B).(2) Grou
25、p 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 the following questions. Present their opinions to o
26、ther 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 history.(3) The
27、 earth 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 the atmosphere.(5) Without the greenhouse effect, the earth would not be warm enough for humans to live.(6) A warmer earth may le
28、ad 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 programs to find out how the climate may change in the years ahead.(8) Global warmin
29、g may be a big problem, but there are many little things we can do to make a difference.Step 5. Reflective thinkingFirst show the following questions to Ss and then ask Ss to discuss them in groups.1. What do you think cause global warming?2. How does global warming affect you and others?3. How does
30、 global warming affect the nature?4. When do you send gases into the air, which affect the earth? (Use the air conditioner, ride in a car, and use a fridge)Step 6. Homework1.Use the new words and expressions to make some sentences.2.Try to write a short composition .The title is “How to slow climate change”, beginning with “Global warming does not have to occur .It is possible for the human race to slow down global warming and may be even remove all of the effect that people have on the climate.”10
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