1. 了解全球气候变暖、生态环境恶化等背景知识；

2. 掌握重要词语和句型的用法、understatement等修辞方法；

3. 理解课文内容，熟悉文章主题思想和语篇结构；

4. 掌握说明文的写作特点，并能使用文体分析方法对说明文进行赏析。

1. 课前收集有关生态环境恶化、全球气候变化等方面的资料，通过查阅工具书和参考书，理解课文中的语词和并熟悉课文主旨内容；通过教师课上讲解和操练，理解课文中的长难句，掌握文章写作技巧和修辞方法，熟悉课文语篇结构；完成教师指定的课后练习和知识拓展练习。

2. 单元重点

掌握understatement、alliteration、metaphor、synecdoche、contrast等修辞方法 
掌握expository writing 的写作特点

3. 单元难点

说明类文体的写作方法

1. Background Information

Al Gore was born in 1948 in Washington D.C., U.S. He has been a Senator (1984~1992) representing the State of Tennessee, and U.S. Vice-President (1992~2000) under President Bill Clinton. He ran for the Presidency against George W. Bush but the latter won the closely tied election and has become the 43rd American President. After retirement, he devoted his time to environmental protection. The text is taken from Al Gore’s book Earth in the Balance.

The Aral Sea, located in Uzbekistan and Kazakhstan (Both countries were part of the former Soviet Union), is historically a saline lake. It is in the centre of a large, flat desert basin. The Aral Sea is a prime example of a dynamic environment.

2. Text Analysis

This piece is taken from Al Gore’s book Earth in the Balance.

The text is an exposition, the purpose of which is to explain to human beings the serious ecological problem resulting from human activities. It is developed in the ways of comparison, contrast, analogy, identification, illustration, analysis, definition, etc.

3. Structure of the Text

The text is divided into three parts:

Part1 (paragraph1 to 8): the list of the images of environmental destruction;

Part 2 (paragraph 9 to 16): analysis of the global threats posed by the environmental destruction and the common cause — the change in the relationship between human civilization and the earth’s natural balance;

Part 3 (paragraph 17 to 26): the solution to environmental destructions — reinventing and healing the relationship between civilization and the earth

4. Key words and Expressions

bleak, lap, at the very bottom of, parka, crack, peel, emission, accessible, thus far, pick up speed, rising level, upwind, runway, monitor, chart the course, pitch, slab, frigid, snowmobile, rendezvous point, hover, take on, resubmerge, eerily, windswept, scenario, a still controversial claim, the pattern of ice distribution, billowing, latitude, noctilucent, cloak, shimmer, translucent, release, landfill, swarm, biomass, startle, spectral, massive, paralysis, be reserved for, in a global context, aquifer, large oil spill, concentration, equilibrium, in turn, in prehistoric times, in one’s search for, acceleration, ongoing, exponential, subsequent, inspiring, obsolete, reinvent

5. Analysis of Rhetorical Devices

understatement; alliteration; metaphor; synecdoche; contrast; etc.

6. Writing Techniques

1) Effective use of verbs to make the exposition vivid and lively 

2) The Analysis of the environment is in light of the military, which helps to arouse the readers’ interest and concern.

3) the purpose of expository writing: to explain or inform.

4) ways of organizing an expository writing: example; definition; comparison and contrast; division and classification; process analysis; causal analysis.

Paraphrase:

1. The prospects of a good catch looked bleak.

2. He moved his finger back in time to the ice of two decades ago.

3. Considering such scenarios is not a purely speculative exercise.

4. To come to the question another way...

5. we seem oblivious of the fragility of the earth’s natural systems

Key:

1. It was not at all possible to catch a large amount of fish.

2. Following the layers of ice in the core sample, his finger came to the place where the layer of ice was formed 20 years ago.

3. Bit by bit trees in the rain forest are felled and the land is cleared and turned into pasture where cattle can be raised quickly and slaughtered and the beef can be used in hamburgers.

4. To put forward the question in a different way…

5. We seem unaware that the earth’s natural systems are delicate

delicate

辩论模拟：Human Civilization: Devil or Angel

要求：2-3名同学为一组，以小组为单位，就人类文明的利弊进行辩论，时间不少于20分钟。

Written work:

1. How has human civilization now become the dominant cause of change in the global environment?

2. Write a short composition on: Ecological Protection

Key:

1. Human civilization is now the dominant cause of change in the global environment. It is hard to imagine and accept, but it is indisputably true. During the last century, there occurred great changes in two aspects: the sudden great surge in population which means every ten years, a population as large as that of China is added to the world; and a sudden acceleration of the scientific and technological revolution, which has enlarged our power to affect the world to an unbelievable degree. So we build more houses of concrete; so we change the surface of the earth with burning, cutting, digging, moving and so on; so the earth have to hold a population which increases at an unprecedented speed; so all the new technologies combine to transform the material substance of the world. Now we come to see the human power which can harm the world in the most comprehensive and permanent way.

2.

With the development of human civilization, man has created countless wonders, but at what a price! Our ecological system, on which all animals’ existence depends, has been seriously damaged and is still being threatened. The earth’s temperature is getting higher, more and more forests are being felled, large numbers of animals are facing extinction, and deserts are expanding at an incredible rate.

The causes for the worsening ecological system are manifold. Perhaps two of the major problems lie in people’s pursuit of short-term interests with little attention to long-term interests and their pursuit of individual interests rather than collective interests. In the first case, many lakes are filled to grow crops or even build houses; trees are cut down, only bare mountains stand cold in the wind and are capable of holding no water when it rains. In the second case, scenic spots become dirty and deserted because of newly established nearby factories producing waste water and air; industrial countries invest heavily in chemical factories in the Third World nations, keeping their own land relatively clean.

To solve the problems mentioned above, we should try our best to balance short-term interests with long-term ones by making long-term plans and taking as many things as possible into consideration. We’re living today and are still to live tomorrow we and our posterity both have to live on the earth. Besides, Global action should be taken to protect our ecological system. People, eastern or western, rich or poor, should join their hands to prevent our ecological system from being further damaged. We have only one earth and we have to make it a better world.

Read the following essay about college students’ out-of-class activities, and 
★ find the thesis statement, four examples and the conclusion;
★ pay attention to how the writer uses the four examples to support a point;
★ study the structural elements that hold the essay together.

Out-of-Class Activities

1. All work and no play can be almost as bad as all play and no work. Getting your degree should be one of your main goals. Your college classes should, and do occupy much of your time, but you also need to develop friendships and get involved in other activities. Involvement in extracurricular groups promotes interpersonal communication and leadership skills. Many students think that the only place to meet people on campus is the student union or student center. However, many other groups provide opportunities for enjoying fellowship with other students. 
2. First, students may join a sports group, which organizes athletic events and services for students. These activities focus on competition that encourages sportsmanship and leadership as well as improves health and gives fun. Second, students interested in the same subject often form a club through the student affairs office. This helps them develop friendships with others. Third, students might join other kinds of clubs on campus that involve individuals with similar interests or hobbies. Membership often depends on grade point average or other criteria. Finally, leisure or other noncredit courses also provide opportunities for you to meet others.
3. In general, students can always take part in some kind of out-of-class activities and communicate with other people to develop their social skills. Thus, they no longer simply attend college; they are part of college life.

Key

1) Thesis statement: However, many other groups provide opportunities for enjoying fellowship with other students.

2) Four examples: In second paragraph, first …; second …; third …; finally…

3) Conclusion: The third paragraph

1. What is global warming? What does ecological environment deterioration include?

2. How can the deterioration be reduced and even prevented?

Key:

1. Global warming is a mix of rising temperatures on our planet, and erratic climate change. A rise in temperature and wacky weather go together. Ecological environment deterioration includes water deterioration, climate changes, smog, land desertification, etc.

2. Immediate actions must be taken to reduce global warming emissions and prevent these consequences from growing more costly and severe in the future. For example, emissions of heat-trapping gases must be brought under control and the impacts of climate change must be reduced.