约3520字。

　　Unit 20 Mainly Revision 
　　一、教学目标与要求
　　本单元的复习重点是第15至19单元出现的有关语法项目和日常交际用语。通过复习，使学生进一步巩固这些语言知识，增强和提高运用这些语言知识表达的能力。语言运用得体，语法正确，表达流畅。经阅读本单元课文，使学生了解到我国古代劳动人民的智慧及纸的发明对世界的影响。并能用自己组织的语言简述中国两千多年的造纸史。
　　二、教学重点与难点
　　1．重点词汇development；press；form；include；describe；come out；throw away；atthe same time
　　2．重要句型1）In the beginning they used to carve Chinese characters on stones torecord important dates in history．2）It took a long time to carve a page for a book．3）It isbelieved that before writing was developed，people in China used to keep records by putting anumber of stones together．
　　3．语法复习第15至19单元学习过的语法项目。
　　4．日常交际用语复习第15至19单元出现过的日常交际用语项目。
　　三、课型
　　（一）对话课 
　　Ⅰ．教具 录音机，投影仪，仿对话中插图内容，准备几件道具，如：石板、木刻板等。
　　Ⅱ．课堂教学设计
　　1．教师通过以下步骤导入本课：
　　向学生提出下列问题：1）Do you know the four great inventions of old China？（com-pass；printing；gunpowder and paper-making）2）Do you think that they are important？Why？Please give examples to show that they are important．
　　组织学生讨论这个话题。同学们可以说出自己的各种想法。例如：
　　Without compass，men will not be able to sail at sea．They will certainly get lost．
　　Without printing，one can not read anything printed in books，newspapers or maga－zines．What a terrible world it must be！Without paper－making，how can you have yourbooks，dictionaries and so on？
　　2．准备放对话录音。借助投影片打出以下听前提问：What did people do to record infor－mation before printing was invented？
　　放录音一至两遍，请学生回答上述问题，教师予以必要订正。
　　Key：People had to carve Chinese characters on stones to record information．For exam-ple，important days in history．
　　3．再次放对话录音，学生跟读。将学生分为两人一组练习对话。
　　经数分钟练习后，请同学将对话中有关印刷术的发展步骤列出。
　　4．要求学生将该课对话改写为一篇短文，描写印刷术在中国的发展。教师可给予必要的提示。
　　Try to use the information from the dialogue to describe the development of printing inChina．
　　提示语：1）use other ways to record information；2）carve Chinese characters on stones；3）developed a way of printing，using rocks；4）carve the characters on a piece of paper；5）brush ink and press a piece of paper
　　教师给出首句：People had to use other ways to record information before printing wasinvented．At first...
　　学生根据提示和教师给出的首句编写短文。
　　Model：
　　People had to use other ways to record information before printing was invented．Atfirst they used to carve Chinese characters on stones to record important days in history．
　　Later people developed a way of printing，using rocks．After they carved the characterson rocks，they put a piece of wet