选修六unit4ReadingPPT课件.pptx

Pre-reading
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1. Have you ever seen a greenhouse?
is made of glass
used for growing plants, especially during cold weather.
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2. How does the greenhouse work?
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The air inside was warm because the
glass traps(挡住, 吸收) the heat from the
sun and keeps it from escaping(逃跑).
This makes the greenhouse heat up(热量
上升) and so the plants can grow
throughout(在…期间) the cold period.
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3. What are Greenhouse Gases?
Methane
4
Ozone
5
1
Carbon dioxide
2
Water vapor
1
1
Nitrous oxide
3
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4. Greenhouse Effect
Global warming
Greenhouse gases trapped the heat from the sun, which causes the temperature of earth goes up.
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Greenhouse effect
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Green house effect
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