2014年高二英语（人教版选修6）教学精品课件：Unit 4 Period Ⅰ.ppt

教师用书独具演示 演示结束 During the 20th century the temperature of the earth rose about 1. degree Fahrenheit. The burning of 2. like coal，natural gas and oil to produce energy. The levels of carbon dioxide have 3． greatly over the last 100 to 150 years.Charles Keeling found that the carbon dioxide in the atmosphere went up from around 4. parts to around 370 parts per million between 1957 and 1997. Dr Janice Foster says that the amount of warming could be as low as 1 to 1.5 degrees Celsius， but it could be as high as 5 degrees over the next 5. years. The climate could be very serious A rise of several metres in the 6. ． Severe storms，floods， 7． ，famines. The spread of diseases. The disappearance of 8. ． We should not worry about high levels of carbon dioxide in the air.It will make plants grow 9. ；crops will produce 10. ；it will encourage a greater range of animals.