Unit4《Globalwarming》thefourthperiod课件（新人教版选修6）.ppt

;Unit 4; Teaching methods situational teaching method ; cooperative learning method; programmed teaching method; task-based and assessment teaching methods.;Teaching aims and demands;Arrangement of teaching;;Discovering useful words and expressions (P28);1. Charles Keeling collected ______on the carbon dioxide content in the atmosphere over a forty-year period. He found that the amount of carbon dioxide _______ increasing during that time.;2. Although we are burning coal in huge _________ every year, we wont ________ of it for centuries. 3. If the amount of greenhouse gases continues to _______, we could be facing a global __________ .;4. Many scientists believe that global warming has __________ through the burning of fossil fuels. ;6. On the whole the warming of the earth is a ____________ that causes great concern. 7. The __________ shows temperature changes during the 20th century. 8. One hectare of forest can absorb 23 tons of carbon dioxide ____ year.;9. The washing machine uses too much energy, but _________ we buy a more economical one, it would still use too much water. 10. The car accident on the main road yesterday ___________ one driver’s death.;1. come about 发生；造成 常用于疑问句（与how连用）和否定句 How did the drought in the southwest of China come about ? John woke up and found he was in hospital but he didn’t know how that had come about. ;come about come across come along come to come on come out come up come up with; Please tell me how the accident_____. I am still in the dark. A. came by B. came out C. came to D. came about;It’s already 10 o’clock. I wonder how it ____ that she was two hours late on such a short trip. came over B. came out C. came about D. came up ;2. subscribe (to) 同意；赞成；订购 Actually, she doesn’t subscribe to your opinion. Which journals does the library su