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(共38张PPT)
Section C
The earth is 4.6 billion years old.
We humans have lived on the earth for only 35 000 years.
During this period, we have changed our planet a lot in many ways.
Our earth is facing all sorts of environmental problems.
What problems does it mention
Fewer trees
Factory pollution
Traffic
pollution
The ozone hole
More carbon dioxide
All these problems are very serious.
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.
C. 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.
A. Traffic pollution
B. Factory pollution
D. The ozone hole
_____________________ 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.
E. More carbon dioxide
Read and understand
cut down, millions of,
take away the earth,
become desert,
disappear
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 and the rich land have become desert.
So more and more sorts of animals and plants are disappearing.
No.1 Fewer trees
cities, pollute,
health problems
In big cities, cars and buses have polluted the air.
Many people in cities now have health problems.
No.2 Traffic pollution
factories,
the land and the water,
dead
Factories have also polluted the land and the water.
As a result, many rivers and lakes are now dead.
No.3 Factory pollution
干涸
No.4 The ozone hole
oxygen
a special kind of oxygen
called “ozone” (O3)
臭氧
the ozone layer
臭氧层
Much radiation from the sun is harmful to us.
It can cause cancer.
radiation
The ozone layer can prevent the harmful radiation from reaching the earth directly.
There is a very big hole in the ozone layer.
As a result, too much harmful radiation
from the sun passes through the hole and reaches the earth directly.
ozone hole
the greenhouse effect
No.5 More carbon dioxide
Carbon dioxide in the air has increased a lot.
It mainly comes from burning oil, coal and wood.
It forms a “blanket” around the earth.
The heat from the sun can’t escape so the temperature is rising.
carbon dioxide
It causes the level of the oceans to rise and
the climate of the earth to change.
1. rise VS raise
rise - rose - risen vi. 升起、上升、起立，
说明主语自身移向高的位置。
太阳从东边升起。
The sun rises in the east.
鱼儿游到湖面。
The fish rise to the surface of the lake.
raise - raised - raised vt. 举起、提起，抬高，
说明主语使其他事物移向高的位置。
raise the hand / head / one’s glass to sb.
价格被提高了。
Prices have been raised up.
价格上涨了很多。
Prices have risen a lot.
强调人为的因素
强调客观的因素
Read and understand
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.
Read 1a again and choose the best answers.
2. What does our planet mean here
A. The sun. B. Mars.
C. The moon. D. The earth.
3. 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
3. The word it in Paragraph 5 refers to ____.
A. CO2 B. O3 C. O2 D. H2O
1b
5、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
2.refer to sb. /sth.
谈及/ 说起 /指的是,
比mention sth. / sb. 更为正式
他曾几次提到过你。
He referred to you several times.
你是说我吗？
Are you referring to me
住在地球上
在此期间
在很多方面改变我们的星球
砍掉了数百万的树木
带走
有健康问题
使臭氧层出现了一个大洞
大量来自太阳的有害射线
通过那个洞直接到达地球
致癌
在地球周围形成毯子似的覆盖层
引起海平面上升
引起地球气候变化
Find the phrases
住在地球上
live on the earth
在此期间
during the period
在很多方面改变我们的星球
change our planet in many ways
砍掉了数百万的树木
cut down millions of trees
带走
有健康问题
have health problems
使臭氧层出现了一个大洞
make a very big hole in the ozone layer
take away.
Find the phrases
大量来自太阳的有害射线
too much harmful radiation from the sun
通过那个洞直接到达地球
pass through the hole and reach the earth directly
致癌
cause cancer
在地球周围形成毯子似的覆盖层
form a “blanket” around the earth
引起海平面上升
cause the level of the oceans to rise
引起地球气候变化
cause the climate of the earth to change
1.First you must dig a _____ before planting a tree.
2. The price of house has ______rapidly these days. We can hardly afford it.
3. The bird has ________(逃跑）from the cage.
4._____ ______ _________(温室效应）makes the earth warm.
5.He went home_________(直接)without telling his teacher.
6.What has he ____________(提及）in his speech
Practice!
hole
risen
escaped
The greenhouse effect
directly
referred to
Exercise
我注意到他拿走了我的书。
I noticed him take away my book.
2. 据说那个孩子从他的钱包里拿走了1000元。
It’s said that the child took 1000 yuan away from his purse.
3. 一些学生在跑步，而其他的在打排球。
Some students are running while others are playing
volleyball.
4. 昨天一只老虎从动物园逃出来了。
A tiger escaped from the zoo yesterday.
5. 温室效应已经导致海平面上升。
The greenhouse effect has caused the level of the oceans
to rise.
6. 向别人敬酒时要举起酒杯。
Raise your glass when you drink to others.

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