Section C

Section CThe main activity is 1a. 本课重点活动是1a。

Ⅰ. T eaching aims and demands 教学目标1. Learn some new words and phrases:on earth, period, millions of, take away, rise, level, refer to2. Learn some useful sentences:(1) When it rains or when the wind blows, the earth is taken away.(2) The heat from the sun can’t 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 are 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 earthdirectly.(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 protection.Ⅱ. T eaching aids 教具图片/小黑板Ⅲ. Five-finger T eaching Plan 五指教学方案Step 1 Review 第一步复习(时间:4分钟)通过检查作业，引导学生开拓思维，提出保护环境和水资源的具体措施，复习不定代词和副词。

为学习新词汇作准备。

(检查作业，并找学生汇报结果，引导学生如何保护水资源。

)T: How do you protect our environment and save water?S1: Everyone should plant more trees.S2: We should do everything we can to save water.S3: Everybody should know the importance of forests.S4: Pass laws against water pollution.S5: Collect and reuse waste water.…Step 2 Presentation 第二步呈现(时间:18分钟)教师通过日常对话，借助1a中的图片，创设情景，导入新课，呈现新的词汇。

1. (教师由日常对话，引出本课话题，呈现部分新词汇。

)T: What’s the weather like today?Ss: It’s …T: As we know, Beijing often has sandstorms in spring. What causes the bad weather?Ss: Cutting down too many trees.(展示1a第二幅图画。

)T: Y es. All over the world, people have cut down millions of trees. And trees become fewer.)T: Cutting down too many trees causes the bad weather. How can trees affect the weather?S1: They can keep water from running away.S2: They can stop …S3: …T: Y es. Trees can stop the wind and water from taking the earth away.)2. (继续探讨上述问题，引出新词汇。

)T: Anything else?(如果没有学生回答，继续如下问题。

)T: What’s the air like in the forest?Ss: It’s fresh.T: Y es. Why?Ss: (允许学生用汉语回答。

)树能吸收二氧化碳并释放氧气。

T: That’s right. Trees can breathe in carbon dioxide and breathe out oxygen.(展示1a第五幅图。

)Please look at the picture.)T: Where does CO2 come from?S4: Animals’ breathing.S5: Burning oil. For example, cars and buses.T: Y es. They have polluted the air. Carbon dioxide in the air has increased a lot. This has formed a “blanket” around the earth.(板书并要求学生理解。

)T: The heat from the sun can’t escape, so the temperature is rising.(板书并要求学生掌握rise；理解escape。

)T: This is called “the greenhouse effect”.)T: What happens to the icebergs(冰川)?Ss: Some parts of them change into water.T: So it causes the level of the oceans to rise.)T: (展示1a第4幅图。

)Please look at this picture. Around the earth, there’s a special kind of oxygen called “ozone”.)T: But now air pollution is destroying it and that has made a very big hole in the ozone layer.)T: Too much harmful radiation from the sun passes through the hole and reaches the earth.)3. (让学生快速阅读1a，用所给的词组填空。

完成1a。

)T: 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. Now read the passage and then choose a proper title for each paragraph from the phrases above the passage.)(学生完成后与教师核对答案。

)(让个别学生回答，完成小黑板上的问题。

)Step 3 Consolidation 第三步巩固(时间:8分钟)让学生再次读1a，完成1b，巩固本课的语言点，培养学生的阅读能力。

1. (让学生再次读课文，完成1b。

)T: Read the passage again. Finish 1b alone.Mars和refer to的汉语意思。

掌握refer to；了解Mars。

))2. (让学生齐读课文，保证每一个学生参与其中。

)T: Now please read the passage together.3. (教师让学生讨论并找出新的或不懂的语言点，培养学生的自主学习能力。

教师解释学生仍有疑惑的知识点并板书。

)4. (让学生两人一组讨论，完成下面的表格。

)T: How many kinds of pollution are mentioned in the passage? How do they affect our environment? According to 1a, finish the form on the blackboard.Step 4 Practice 第四步练习(时间:10分钟)使学生了解各种污染对地球环境的影响，培养他们的环保意识。

1. (让学生分组讨论，看哪组最快说出O3，CO2和温室效应的含义及其对环境的影响，并以此写一篇短文，完成2。

)T: Please read the passage again, discuss the meanings of the following expressions in 2 in groups of 4, and then write down how they affect the environment.(学生讨论后，与教师核对答案。

)2. (根据给出的提示词写一篇小短文，可先口述。

)T: Write a short passage with the key words given.Step 5 Project 第五步综合探究活动(时间:5分钟)让学生讨论各种危害地球的污染方式，并就有关污染写一篇短文，培养学生综合运用语言的能力，增强学生的环保意识。

1. (到目前为止，污染危害地球的方式已基本介绍完毕，可以让学生做专题讨论，以锻炼他们组织语言的综合能力。

在此过程中，鼓励学生大胆发挥，做最大程度的拓展性讨论。

最后通过汇报，教师检验活动成果。

)T: OK, until now, we have learned so many kinds of pollution. Now please work in groups and discuss them. After a moment, I’ll ask some students to report it.2. Homework:Write an article about the pollution.板书设计：课后小结本节课介绍了人类一些活动对环境造成的污染破坏，并描绘了这些活动是如何造成破坏的，提醒人们减少污染，保护环境。