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仁爱英语九年级unit2topic2sectionC课件

发布时间:2013-11-30 16:33:55  

Unit 2 Saving the Earth
Topic2 All these problems are very serious.

Section C

教学资源共享

In our daily life, we should face more environmental problems. Can you say something about them?

cities, pollute, health problems

In our daily life, we should face more environmental problems. Can you say something about them?

factories, the land and the air, dead

In our daily life, we should face more environmental problems. Can you say something about them?

cut down, millions of, take away the earth, become desert

In our daily life, we should face more environmental problems. Can you say something about them?

oxygen

a special kind of oxygen called “ozone” (O3)

a very big hole in the ozone layer, too much harmful radiation from the sun

臭氧层视频

In our daily life, we should face more environmental problems. Can you say something about them?

CO2 carbon dioxide increase a lot, form a “blanket”, the heat from the sun can’t escape

cause the level of the sea to rise called “the greenhouse effect” or “globe warming”

温室效应:视频1, 视频2

What other kinds of environmental problems can you think of? Talk about them with your classmates.

Can you match them?
traffic pollution

factory pollution

more carbon dioxide

the ozone layer fewer trees

Fewer trees

Factory pollution

Traffic pollution

The ozone layer More carbon dioxide

All these problems are very serious. What can we do to solve them?

(影片)

Read and understand

Can you choose a suitable title for each paragraph from the phrases below? The earth is 4 600 million years old. We humans have lived on earth for only 35 000 years, but during this period we have changed our planet a lot in many ways. Some things we’ve done are very good for the earth while some are bad. Fewer Trees _________ All over the world, people have cut down millions of trees. When it rains or when the wind blows, the earth is taken away. Forests have become deserts, so more and more sorts of animals and plants are disappearing.

Traffic Pollution In big cities, cars and buses have ____________

polluted the air. Many people in cities now have health problems. Factory Pollution _____________Factories have also polluted the land and the water. As a result, many rivers and lakes are now dead. The Ozone Layer _____________ Around the earth, there’s a special kind of oxygen called “ozone”(O3). It is important to the earth. But now air pollution is destroying it and that has made a very big hole in the ozone layer. Too much harmful radiation from the sun passes through the hole and reaches the earth directly. This is very dangerous because this kind of radiation can cause cancer.

More Carbon Dioxide ________________ Carbon dioxide (CO2) in the air has increased a lot. It mainly comes from burning oil, coal and wood. This has formed a “blanket” around the earth. The heat from the sun can’t escape so the temperature is rising. This is called “the gre

enhouse effect”. It causes the level of the oceans to rise and the climate of the earth to change. All these problems are very serious, so we must do something now.

Read 1a again and choose the best answers.

1、What does our planet mean here? A. The sun. B. Mars. C. The moon. D. The earth.

Read 1a again and choose the best answers.

2、Which is NOT true? A. Cars can pollute the air. B. Factories can pollute the water. C. The fewer trees, the better. D. Not all the things we have done are good for the earth.

3、The word it in the passage refers to ____. A. CO2 B. O3 C. O2 D. H2O

Read 1a again and choose the best answers.

4、In the passage, “blanket” refers to ____. A. carbon dioxide around the earth B. the ozone layer in the sky C. the forests around the world D. pollution all over the world

5、The level of the oceans is rising because of ____. A. pollution B. few trees C. the greenhouse effect D. changes in the climate

Read 1a again and choose the best answers.

6、What is the best title for this passage? A. Environmental Problems B. Pollution on the Earth C. Hope for the Future D. The Greenhouse Effect

Written work
Discuss the meanings of the following expressions and then write down how they affect the environment. O3: A special kind of oxygen called “ozone”

Ozone is very important to the earth.
The ozone layer can prevent the sun's harmful radiation from reaching the earth. But now air pollution is destroying the ozone layer. This is very dangerous because this kind of radiation can cause cancer.

Written work
Discuss the meanings of the following expressions and then write down how they affect the environment.
CO2: Carbon dioxide. It mainly comes from
burning oil, coal and wood.

the greenhouse effect: Carbon dioxide around
the earth makes the temperature rise.

More and more carbon dioxide forms a “blanket” around the earth. The heat from the
sun can't escape so the temperature is rising. It causes the level of the oceans to rise and the climate of the earth to change.

Group work
Are you a green person? Do you want to know how many people are turning green in your class? Work with your partners and design a questionnaire(问卷 调查) like this. How many kinds of pollution do you know? …

Useful expressions
… people have cut down millions of trees.

… the earth is taken away.
The heat from the sun can’t escape so the temperature is rising. It causes the level of the oceans to rise …

Bye-bye!


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