(共22张PPT)
Unit 2 Saving the Earth
Topic2 All these problems are very serious.
Section C
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.
fewer trees
factory pollution
traffic pollution
the ozone layer
more carbon dioxide
Can you match them
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
Read and understand
（影片）
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.
_________ 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.
Fewer Trees
____________ In big cities, cars and buses have polluted the air. Many people in cities now have health problems.
_____________Factories have also polluted the land and the water. As a result, many rivers and lakes are now dead.
_____________ 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.
Traffic Pollution
Factory Pollution
The Ozone Layer
________________ 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 greenhouse 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.
More Carbon Dioxide
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
Ozone is very important to the earth.
O3:
Written work
Discuss the meanings of the following expressions and then write down how they affect the environment.
A special kind of oxygen called “ozone”
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.
CO2:
the greenhouse effect:
More and more carbon dioxide forms a “blanket” around the earth.
Written work
Discuss the meanings of the following expressions and then write down how they affect the environment.
Carbon dioxide. It mainly comes from burning oil, coal and wood.
Carbon dioxide around the earth makes the temperature rise.
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!
