Unit4GlobalwarmingReading课件人教版选修6.ppt

;Reading ; What is the greenhouse made and used for?; A greenhouse is made of glass and is used for growing plants, especially during cold weather.;How does it work? The air inside is warm because the glass traps the heat from the sun and keeps it from escaping. This makes the greenhouse heat up and so the plants can grow throughout the cold period.;What are the “greenhouse gases”? In the atmosphere surrounding the earth there are gases, which are called “greenhouse gases”, including carbon dioxide, methane(甲烷, 沼气) and water vapor.;What do you think greenhouse gases do? They trap heat from the sun and therefore warm the earth.;Main ideas of each part;Main ideas of each part;;;Read the text carefully and fill in the blanks.;Scientists;Scientists;Choose the best answers. 1. Which of the following is TRUE according to the text? A. The temperature of the earth increased about one degree Fahrenheit during the 20th century. B. The carbon dioxide content in the air increased by 70 parts per million from 1957 to 1997. C. All scientists accept the data in graph 2 except Charles Keeling. D. Janice Foster says that more carbon dioxide will make plants grow faster.;2. Which of the following is Dr Janice Foster’s opinion? A. The result of the temperature increase will be serious. B. The amount of warming is nothing serious. C. We needn’t worry about high levels of carbon dioxide. D. Global warming is a natural phenomenon.;;浓度单位;Glance quickly at the magazine article and answer the questions. Who wrote the magazine article? What is the name of the magazine? Sophie Armstrong wrote the magazine article. The name of the magazine is Earth Care.;What are the names of the three scientists mentioned in the article? They are Dr. Janice Foster, Charles Keeling and George Hambley.;3. What do they think about global warming? Do they agree with one another? They dont agree with each other.