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《Warming up、Pre-reading、Reading、Comprehending》集体备课PPT课件优质课下载
Does that mean we should do nothing? Or, are the risks too great?
During the 20th century the temperature of the earth rose about one degree Fahrenheit. That probably does not seem much to you or me, but it is a rapid increase when compared to other natural changes.
So how has this come about and does it matter?
Learning about the structure
Exploring the facts for para1
1. The earth is becoming warmer.
2. It is human activity that has caused this global warming
rather than a random but natural phenomenon.
global warming in history
A. wobbles（摇晃） in the earth's orbit(轨道).
B. increase of greenhouse gases in the atmosphere.
C. sometimes the earth gets too close to the sun.
global warming nowadays
Exploring the facts for para2
The increase in the earth's temperature is due to the burning
of fossil fuels like coal, natural gas and oil to produce energy.
A report on the greenhouse effect
1. greenhouse gases are produced when __________________
2. Greenhouse gases include:
________________
________________
________________
carbon dioxide (co2)
methane
water vapour