Unit 2 Saving the Earth Topic 2 All these problems are very serious. Section C 课件(
课件网) Teaching aims 学习目标：1、掌握本课的重点词汇和短语； 2、进一步学习各种污染对地球造成的危害和 造成这些污染的原因。 情感目标：通过学习，了解环境现状，帮助学生树立绿色 环保意识。 教学重点：正确运用不定代词和副词；阅读策略的运用。 教学难点：运用所学知识，完成谈论环境保护的文章。 检查预习稿 Lead in How old is the earth 4.6 billion years old. What about humans We humans have lived on the earth for only 35 000 years. Look and Predict. Pre-reading Read the passage and choose. 5. What is the best title for this passage A. Environment Problems B. Pollution on the Earth C. Hope for the Future D. The Greenhouse Effect While-reading _____ _____ _____ the earth we must do something problems and effects Environmental problems Part1: Part 2: Part 3: ① ②--⑥ ⑦ What is the structure of this passage Read for details. Part 1 How old is the earth 4.6 billion years old How long have we lived on the earth 35,000 years Has our planet changed a lot Yes 2. What does our planet mean here A. The sun. B. Mars. C. The moon. D. The earth. The earth is 4.6 billion years old. We humans have lived on the 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. Paragraph 1 1. on the earth 在地球上 2. during this period 在这个时期 3. change our planet a lot 大大改变了我们的星球 4. be good for 对......有好处 1. Choose suitable titles for Paragraphs 2-6. Then write it down in front of each paragraph. A. Traffic pollution B. Factory pollution C. Fewer trees D. The ozone hole E. More carbon dioxide fewer trees factory pollution traffic pollution the ozone layer more carbon dioxide Part 2 carbon dioxide 二氧化碳 /‘ka: b n dai’a: ksaid/ ozone 臭氧 /’ uz un/ _____ 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 many kinds of animals and plants are disappearing. Fewer Trees Paragraph 2 1. all over the world 全世界 2. cut down 砍伐 3. millions of trees 数以百万计的树木 4. take away 拿走，取走 _____ In big cities, cars and buses have polluted the air. Now many people in cities 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 making 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 Ozone Hole 直接地 Paragraph 3-5 1. a special kind of oxygen 一种特殊的氧气 2. make a very big hole 形成一个非常大的洞 3. ozone l ... ...
