Unit 2 Saving the earth 一、教学目标与要求 通过本单元学习，学生了解地球当今所面临的重大污染问题。如对空气、水的污染现状和造成的严重后果；了解人类活动对我们周围环境造成的破坏，以及对动物生存造成的极大威胁，使学生能更好地树立环保意识。学生能用英语描述以上内容，并通过讨论，得出自己的看法和人类应采取的措施。使英语学习和语言能力的提高与增强环保意识结合起来；通过对话课的学习与操练，学生复习有关表示同意和假设的用语；学习并初步掌握过去分词作定语和表语的用法；正确完成练习册安排的练习。 二、教学重点与难点 1．重点词汇 damage； pollute； pollution； cause；sight；present； pour； living； proba－bly；separately；unclear waste；be fit for；hear about ； turn…to…；time and time again；lose one’s sight；so that； die out；go off； point to； to one’s joy 2．重要句型 1） It is said that 125 000 people died in Russia as a result of illnesses caused by this accident． 2） Oceans are able to clean themselves， but certain seas， once they become dirty， are not able to do so． 3）There are many reasons for animals dying out，but the most important one is the part that humans have played． 3．语法 过去分词作定语和表语（ The Past Participle as Predicative and Attribute）1） Polluted rivers and lakes have also been a cause of death． 2） One suggested answer is for farmers to limit the numbers of their cattle． 3） Another problem is that good soil is gradually lost ．4） One quarter of the shores of the Mediterranean are polluted． 4．日常交际用语 同意和假设（Agreement and supposition） 1）It’s a good idea to hold such conferences． 2） Yes． If we go on polluting the world，it won’t be fit for us to live in．3） I agree with you． We’ve got to do something about the pollution． It’s getting worse．4）Yes， it certainly is． If people don’t stop polluting the seas and rive...
