英语必修5译林牛津版Unit 3第1课时表格教案 主备人  执教人  授课日期  班级   总课题 M5U3 总课时  分课时  1 课型 新授  课题 M5U3 Welcome to the unit  教学目标 think more about the relationship between science and nature. describe some items and atmosphere with scientific terms. express their opinions on cloned animals and humans as well. develop an interest in doing more reading and research on the topic.  教学重点 Words , phrases and sentence patterns  教学难点 Practical usage  教具 Blackboard , slides and handouts   教学内容 教法学法  Teaching procedures: Step 1 Lead in (PPT 4-7) Play a dialogue about height-increasing operations and ask students to fill in the blanks. After checking the answers, allow some time for students to freely express their opinions on height-increasing operations, thus introduce the major topic “science versus nature”。 [Explanation] 用一段有关增高术的听力引入主题,主要是考虑到这一切入点与实际生活较为贴近,比较容易让学生有话说,作为人类利用科学对自然的东西做出改变的一个典型例子可以顺其自然得引入本课主题。 Step 2 Science versus nature (PPT 8) Explain the word “versus” ( Two sides are against each other) Brainstorming. Ask students to think of other cases in which science goes against nature? The teacher can introduce some new vocabulary like GM food and plastic surgery which might be useful in later teaching. Show some pictures to help them better understand these things. Suggested answers: GM food, cloning, dams, artificial rainfall, organ transplant, air-conditioner, cloud seeding, plastic surgery, euthanasia, etc. Allow students some time to have a light discussion on advantages and disadvantages of any of the above cases. In terms of science versus nature, what do you think the relationship between science and nature should be like? (Both advance in harmony) [Explanation] 本节将主题定位在“科学对抗自然”,让学生了解了这一关系后,用头脑风暴的形式让学生从增高术联想起更多的现实生活中能体现这一关系的案例,如转基因食品,人工雨等。 Step 3 Cloning (PPT 9-11) Display pictures of Dolly and normal sheep on the screen. Tell them Dolly is a cloned sheep. But it looks no different from normal sheep. Show more pictures of cloned animals ( cloned calves, pigs, monkey and mule). Their names can be introduced here, which might arouse students’ more interest. Introduce the concept of “copy”. Ask the students to think about this question: Are cloned animals exactly the same as the “mother animals”? (They may have the same appearance but their physical qualities can be very different. Many cloned animals died at a much younger age than average.) Interview one student about his feeling towards cloned animals by asking the following three questions: 1) If you happen to have a cloned cat, how would you feel? (excited) 2) What if another cat with the same appearance comes to you? (surprised and more excited) 3) What if more cats with the same appearance come to you? (shocked and scared) Interview another student about his feeling towards a “cloned him”. Then ask the other students if they would like to see a “cloned him” and why. Girls versus boys. Ask students to have a 2-minute debate on whether it would be a good idea to clone humans some day. [Explanation] 本节将讨论的重点转向克隆。通过图片展示的方式让学生对克隆动物有个感性的认识,并引进“拷贝”的概念,与第二课时的阅读标题形成呼应。 Step 4 Summary (PPT 12) Give a brief summary of their debate. Point out any possible problems in their debate like the lack of ideas and supporting points. Tell students that you will read more about cloning in the following period and will have a further discussion. [Explanation] 对学生的辩论进行简短的评价,一是评价学生的表现,二是让学生产生更多的兴趣去阅读,并且阅读的目的性更明确,从而能够保证阅读的成效。   教后记:   高考链接—拓展阅读 Tides(潮汐)are created mainly by the pull of the moon on the earth. The moon's pull causes water in the oceans to be a little deeper at a point closet to the moon and also at a point farthest from the moon on the opposite side of the earth. These two tidal"Waves"follow the apparent(明显的) movement of the moon around the earth and strike nearly every coast line at in- tervals of about twelve hours and twenty-five minutes. After reaching a high point, the water level goes down gradually for a little more than six hours and then begins to rise toward a new high point. Hence, most coast lines have two tides a day, and the tides occur fifty minutes later each day. Differences in the coast line and in channels in the ocean bottom may change the times that the tidal wave reaches different points along the same coast line. Tne difference in water level between high and low tide varies from day to day according to the relative positions of the sun and the moon because the sun also exerts a pull on the earth, although it is only about half as strong as the pull of the moon. When the sun and the moon are pulling along the same line, the tides rise higher, and when they pull at fight angles to one another, the tide is lower. The formation of the coast line and variations(变化)in the weather are additional factors which can affect the height of tides. Some sections of the coast are shaped in such a way as to cause much higher tides than are experienced in other areas. A strong wind blowing toward the shore may also cause tides to be higher. 1. The height of the tide is affected by all of the following except_________. A. the position of the sun B. the direction of the wind C. variations in the coast line D. channels in the sea bottom 答案:D 指导:潮汐的高度受太阳、风向和海岸线差异的影响,海沟只影响潮汐的时间。由文中Differences...in channels in the ocean bottom may change the time.可知。 2. If the pull of the sun equaled the pull of the moon, tides would_________. A. sometimes be higher than they are now B. be the same height as they are now C. no longer be affected by the wind D. be of equal height all the time 答案:A 指导:太阳对地球的吸引力只有月亮的一半(...it is only about half as strong as the pull of the moon)如果相同并作用在一个方向上,潮汐会比目前高。本题必须正确理解设问的意思 3. If one high tide occurs at 1: 00 a. m. , the next high tide at the same point will occur at about_________. A. 1: 25 a.m. the same day B. 1: 00 p.m. the same day C. 1: 25 p.m. the same day D. 1:50 a.m. the next day 答案:C 指导:潮汐12小时一次,每24小时向后延迟50分钟,题干中所给定的时间是12小时间段,故应是25分钟。

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