《九年级英语上册 Unit 2《Topic 2 All these problems are very serious》Section C 课件 仁爱版》由会员分享，可在线阅读，更多相关《九年级英语上册 Unit 2《Topic 2 All these problems are very serious》Section C 课件 仁爱版（24页珍藏版）》请在金锄头文库上搜索。
1、Unit 2,Saving the Earth,Topic 2,All these problems are very serious.,Section C,Teaching aims and demands,1. Learn some new words and phrases:law, turn off, tap, on earth, ozone layer, carbon, period, millions of, take away, pollute, oxygen, radiation, blanket, escape, rise, the greenhouse effect, le
2、vel, refer2. Learn some useful sentences:(1) When it rains or when the wind blows, the earth is taken away.(2) The heat from the sun cant escape so the temperature is rising.,3. Learn to talk about the harm of pollution:(1) Forests have become deserts, so more and more sorts of animals and plants ar
3、e disappearing.(2) As a result, many rivers and lakes are now dead. (3) Too much harmful radiation from the sun passes through the hole and reaches the earth directly.(4) It causes the level of the oceans to rise and the climate of the earth to change.4. Develop the students sense of environmental p
4、rotection.,New words,1a Read and understand,Can you choose a suitable title for each paragraph from the phrases below?,traffic pollution,fewer trees,the Ozone layer,factory pollution,more carbon dioxide,The earth is 4 600 million years old. We humans have lived on earth for only 35 000 years, but du
5、ring this period we have changed our planet a lot in many ways. Some things weve done are very good for the earth while some are bad._ All over the world, people have cut down million of trees. When it rains or when the wind blows, the earth is taken away. Forests have become deserts, so more and mo
6、re sorts of animals and plants are disappearing. _ 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, theres a special kind of
7、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
8、 can cause cancer.,_ Carbon dioxide (CO2) in the air has increased a lot. It mainly comes from burning oil, coal and wood. This had formed a “blanket” around the earth. The heat from the sun cant escape so the temperature is rising. This is called “the greenhouse effect”. It causes the level of the
9、oceans to rise and the climate of the earth to change. all these problems are very serious, so we must do something now.,1b Work alone,Read 1a again and choose the correct answers.,1. What does our planet mean here? A. The sun B. Mars C. The moon D. The earth2. Which is NOT true? A. Cars can pollute
10、 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 earth3. The world it in the passage refer to _. A. CO2 B. O3 C. O2 D. H2O,4. In the passage, “blanket” refers to _. A. carbon dioxide around the earth B. the ozone layer in
11、the sky C. the forests around the world D. pollution all over the world5. The level of the oceans is rising because of _. A. pollution B. few trees C. the greenhouse effect D. changes in the climate6. What is the best title for this passage? A. Environmental Problems B. Pollution on the Earth C. Hop
12、e for the Future D. The Greenhouse Effect,2 Write work,Discuss the meanings of the following expressions and then write down how they affect the environment.,O3: _ Ozone is very important to the earth. _,CO2: _The greenhouse effect: _ More and more carbon dioxide forms a “blanket” around the earth.
13、_,Explanation,1. Some things weve done are very good for the earth while some are bad. 我们所做的一些事情对地球有益，然而另一些却对地球有着负面影响。,（1）weve done 为定语从句，修饰things。（2）while 这里为并列连词，意为“然而，而。 如：,Her sister likes reading while she likes singing.她妹妹喜欢看书，而她喜欢唱歌。They went out, while she stayed at home. 他们出去了，而她留在家里。,2. Al
14、l over the world people have cut down millions of trees. 在全世界，人们已经砍伐了数以百万计的树木。,million, thousand, hundred等数词的复数形式后接of短语，表示数以百万（千、百）计的，指不确定的数目。如：,Men have been making music for thousands of years. 人类创作音乐已有数千年的历史。,3. When it rains or when the wind blows, the earth is taken away. 当刮风下雨的时候土就被刮走或冲走。,take
15、 away 拿走，取走 如：,I dont like these books. Please take them away.我不喜欢这些书，请把它们拿走。,take off 脱下，(飞机)起飞；take 把带到去；take sb. for a walk 带某人去散步；take ones time别着急，慢慢干；take a bus(ship/train)乘公共汽车(轮船/火车)take turns 轮流，替换；take care of 照看；It takes sb. time/ money to do sth. 花费某人时间/金钱做某事；take a look 看一看；take photos 拍照；take a holiday 度假；take a rest 休息一下；take a seat 坐下,
