高中英语Unit 21 Lesson 1 Chewing Gum教案2 北师大版 选修7

Unit 21 Lesson 1 Chewing GumTeaching aims:To read about the effects of chewing gum.To revise conditionalsTo practice using mixed conditionalsTeaching difficulties: some students may not remember the first, second and third conditionals well. The form of mixed conditionals may be difficult for some students to master and they may need more practice with it.Teaching Aids: computer and video rejectionTeaching procedures:Step 1: lead-in1. Show students advertisement an video about gum so as to raise their interest on chewing gum and make them think of the effects of chewing gum in daily life.2. Students work in pairs discussing the questions and require them to share their ideas with class.Discuss in pairs and answer the following questions.What do you think of chewing gum? Is it good or bad for you?Do you or your friends /family buy it? Why?What do you do after chewing it?3. Students look at the title and predict which issues may be covered in the article. Then, students work individually, reading the article quickly to find out which of their guesses were right.Step 2: read to learn1. Students divide the text into four parts, then summarize the main topic of each part.Part 1 (paragraph 1- 1 ) IntroductionPart 2 (paragraph 2 - 4 ) Benefits of chewing gumsPart3 (paragraph 5 - 7 ) The negative sides of chewing gumsPart4 (paragraph 8- 8 )Better activities than chewing gums2. Work individually, students try and fill the table with the information they remember from the first reading. After finishing the table, students discuss it with each other and then check answers as a class. Advantage DisadvantageHelping people:1. fight bad breath2. prevent/ stop tooth decay3. lose weight4. give up smoke1.making digestionsmore difficult2. Causing feelings ofsickness or headaches3. Leading to stomach sickness4. Making people neglect brushing their teeth3. Students work in pairs answering the questions. Ask them to locate the relevant parts in the text which give the answers.1. How serious is the problem of bad breath?2. What is added to sugar-free chewing gum which may help prevent tooth problems?3. According to one research project, what is one way of burning 70 kilocalories?4. What would be the effect on the stomach of constant chewing?5. What other activities are stated that are better than chewing gum?Step 3: grammar1. Students match the conditional sentences in italics in the text with the following types: zero conditional, 1st conditional, 2nd conditional, 3rd conditional. Check students answers by having individuals read out the sentences and then describe them.2.