Unit 4 Global warming

. 1. 教材分析

本单元以Global warming 为主线，旨在通过单元教学使学生经过思考、学习，认识到全球变暖的起因和它所带来的种种后果。同时鼓励学生进一步阐述地球所面临的其它严重问题，激发学生的环保意识。引导学生运用所学语言、句式表达自己对这些现象的看法，培养他们为自己的观点辩论的能力，并能运用所学知识写一篇有关环境问题的论文。

1.3 Reading是一篇从杂志节选的文章。它讲述了全球加速变暖的原因--人为温室效应，后果以及人们对此的不同观点。要求学生在理解文章大意的同时注意它的写作技巧：提出问题--分析现象--阐述各方面的不同观点--以疑问句作为总结引发读者深思，自行做出判断。这为Comprehending 中Exercise 3的分组辩论活动留出了很大的空间，埋下了很好的伏笔。

Teaching goals 教学目标

a. 重点词汇和短语

compare, phenomenon, graph, fuel, trap, data, climate, catastrophe, consequence, range, per, glance, compare to, come about, fierce debate, result in, build up

b. 重点句式

There is no doubt that the earth is becoming warmer. P26

Without the'greenhouse effect', the earth would be about thirty-three degrees Celsius cooler than it is. P26

They also agree that it is the burning of more and more fossil fuels that has resulted in this increase in carbon dioxide. P26

2. Ability goals 能力目标

Enable the students to talk about the causes and effects of global warming.

3. Learning ability goals 学能目标

Help the students learn how to talk about the causes and effects of global warming and express ideas about what people should do about it.