1、A Lesson in a Lab第三课时学习内容（Learning contents）Introduction, Passage A and Passage B 学习目标（Learning aims）1. To master some words and expressions;2.To learn some sentence structures .自主梳理【教材原句】 It is hard to think of a world without metals.(P44)很难想象一个没有金属的世界。【句法分析】 本句中，it 为形式主语，真正的主语是不定式短语 to think of.，构
2、成 It is/wasadj.to d o sth.的结构。It is adj.for sb.to do sth.该句式中，作表语的形容词只能说明不定式的行为性质和特点，不能说明不定式的执行者。常见的这类形容词有：easy，important，difficult，hard，possible，impossible，necessary 等。It isadj.of sb.to do sth.该句式中，作表语的形容词表达不定式的逻辑主语的品行、性格或性质。常见的这类形容词有：kind，nice，good，honest，careful，careless，clever，wise，stupid，foolis
3、h，rude，polite，impolite 等。It isadj./n.that clauseIt isno good/use doing sth.It is easier to say than to do.说比做容易。It is no good playing computer games.玩电脑游戏没有好处。It is a shame that he didnt pass the exam.很遗憾他没有通过考试。It is said that the ticke ts have been sold out.据说票已售完。【教材原句】 Here is a table with the m
4、etals that react most at the top，and the metals that react least at the bottom.(P44)这儿有一个图表，那些反应最强烈的金属在上部，反应最不强烈的在下部。【句法分析】 这是一个倒装句，正常语序是：A table with.is here.(1)在 there ，here 引导的句子中，谓语是 be，exist 等表示状态的不及物动词时，句子要全部倒装。(2)在 there，here，now，then，thus 等开头的句子里，谓语动词是 come，go，follow 等时，句子要全部倒装。(3)here，there
5、 引导的句子，当主语是代词时，不倒装，且此类句子不用进行时。Here are what I want you to do.下面是我想让你做的事情。There goes the bus. 公共汽车走了。Now comes my turn.现在该轮到我了。重点领悟【归纳总结】keep after 追赶keep away 远离keep back 阻止；隐瞒keep down 吞下；镇压；控制keep sb. from doing sth.阻止某人做某事keep off 防止，避开keep on 继续keep to 坚持；履行keep up 不低落；维持，坚持；继续keep up with 跟上You
6、d better keep yourself out of other peoples quarrels.你最好不要卷入别人的纠纷中去。He begged the police to keep his name out of the papers.他恳求警察不要在报纸上披露他的名字。Please keep the dog out of the study.别让这只狗进书房。探究提升(一)expand vi. 膨胀 vt. 扩大，扩充(回归课本 P41) When you heat a metal，it expands.当你加热金属时，它就会膨胀。 Metals expand when they
7、 are heated.金属受热会膨胀。As children grow older they expand their interests and become more confident.随着儿童的成长，他们的兴趣会变广，人也会变得更自信。Could you expand on that point，please?请你把那一点详细说明一下，好吗 conclusion n 结论 (回归课本 P45) Conclusion , Iron rusts in ordinary water.结论：铁在普通水中生锈。draw/come to/arrive at/reach a conclusion
8、得出结论make a conclusion 下结论bring.to a conclusion 使 结束in conclusion 最后，作为结论地；总之conclude v.得出结论； 断定，推断出；结束to conclude 最后conclude from sth.that 从中断定They came to the conclusion that its time Chinese football should be regulated.他们得出的结论是：中国足球到了该整顿的时候了。 In conclusion，I would like to say how much I have enjo
9、yed myself today.最后，我想说我今天过得很开心。 ordinary adj. 普通的，平常的 (回归课本 P45) The nails rust in the tube with ordinary water. 钉子在装有普通水的试管中生锈了。ordinarylooking 相貌平平的，相貌普通的out of the ordinary 不寻常的；例外的in the ordinary way 一般；通常 Jim was not in the ordinary way a romantic，but he decided to bring Mary some roses.吉姆通常并不
10、是一个浪漫的人，但他决定带一些玫瑰花给玛丽。The new taxes came as a shock to ordinary Americans.新税费对普通美国人来说如同一次重击。Nothing out of the ordinary had happened.来源:学科网 ZXXK没发生什么意外之事。What is ordinary in one country may be very strange in another.在一个国家很普通的事，在另一个国家可能很奇怪。【易混辨析】ordinary，common，usual，normal(1)ordinary 普通的，平常的，平凡的。强调
11、等级和类属方面普通。有“平庸无奇”之意。(2)common 普通的，常见的。强调经常发生，司空见惯，可修饰人或物。也可指共同的、共存的。common sense 常识。(3)usual 通常的，惯常的，惯例的，强调依照惯例来判断，有“遵循常规”之意。(4) normal 正常的，合乎标准的。强调在正常情况下应有的。Whoever has common sense knows that smoking is harmful to peoples health.Last Sunday，he went to work as usua l.Free medical treatment in this
12、country covers sickness of mind as well as ordinary_illness.It is known that a persons normal_temperature is about 36.5. react vi. (化学)反应；起作用；起反应(回归课本 P44)it is important to know how they react with different substances.来源:Z.xx.k.Com要了解它们和不同的物质如何发生反应，这一点很重要react to 对作出反应react with 与起(化学)反应react agai
13、nst 反对；反抗react on/upon 对有影响reaction n.反应 How did he react to your suggestion?他对你的建议反应如何？Children tend to react against their pare nts by going against their wishes.孩子们通常以违背父母的意愿来反抗他们。Iron reacts with water and air to produce rust.铁与水和空气起化学反应而生锈。How do acids react on metals?来源:学科网 ZXXK酸对金属起什么反应 ？What
14、 was her reaction to the news?她对这消息的反应如何？ add.to. 把加到(回归课本 P45) Add some oil to the water.This will keep air out of the water.在水中加些油。这样做可防止空气进入水中。来源:学&科&网【归纳总结】add v.加；继续说；补充说add to 增加；增添add up 把加起来add up to 合计达；结果是 来源:学。科。网addition n.加；(数)加法；增加in addition 另外in addition to 除之外Please add some sugar t
15、o the bread.请在面包上加些糖。Three added to four makes seven.三加四等于七。Fireworks added to the attraction of the festival night.烟花使节日之夜更具吸引力。Add up all the figu res and find out what they add up to.把这些数字加起来，弄清楚总计是多少。 keep.out of 使进不去；不让进入；把挡在外面；避开(回归课本 P45) This will keep air out of the water.这将阻止空气进入水中。巩固训练：P50 课后习题。
