必修三unit 4 _教案

1、必修三 unit 4 Astronomy: the science of the stars适用学科英语适用年级高一适用区域全国课时时长分钟2课时知识点1、本单元重点词汇。2、倍数的表达。3、名词性从句中的主语从句。教学目标1、掌握本单元局部单词和短语的根本词义和用法。2、通过本单元的学习 ,要求学生熟练掌握主语从句的语用功能。教学重点通过上下文来教词汇、语法 ,并引导学生分析长句、难句和复杂句。教学难点总结语言材料中有关主语从句的用法和功能并加以应用。教学过程一、 课堂导入Play a game to learn the names and positions of the planets:

2、Venus is next to Mercury.Earth is the third planet.Mars is between Earth and Jupiter.Neptune is the furthest planet from the sun.Saturn is between Uranus and Jupiter.Mercury is closest to the sun.二、复习预习 教师引导学生复习上节课所学知识点 , 以提问、回忆的形式进行 ,针对上节课的作业进行讲评、订正、答疑 ,并通过对主语从句具体用法的分析和扩展导入本节课所要学习的课本知识的学习。 三、知识讲解考点

3、/易错点1 重点单词与短语学习violent adj. 暴力的；猛烈的(回归课本P25) The earth became so violent that it was not clear whether the shape would last or not.归纳拓展 violent criminals: 使用暴力的罪犯 a violent attack: 猛烈的攻击a violent protest：强烈的抗议 a violent struggle； 剧烈的斗争violent winds and storms 狂风暴雨 violent toothache: 剧烈的牙痛in time 及时；

4、最后 (回归课本P25) It exploded loudly with fire and rock. They were in time to produce carbon dioxide, nitrogen water vapor and other gases, which were to make the earths atmosphere. 它地球巨大的爆炸喷出了烈火与岩石 ,最终产生了水蒸汽、二氧化碳、氧、氮和其他多种气体 ,从而形成了地球的大气层。in time: sooner or later; eventually 迟早；最后。in time(for sth/ to do s

5、th) : not late 及时；不迟。in/out of time: in/not in the correct time 合/不合节怕。Eg: Ill see him in time. 总有一天我会遇见他。She will be back in time to prepare dinner. 她来得及回来准备晚饭。归纳拓展 The audience clapped in time to the music. 观众合着音乐的节拍拍手。in no time 立即；马上 at no time 绝不at a time 一次；每次 at one time 曾经；一度at times 有时 ahea

6、d of time 提前for the time being 暂时 take ones time 别着急；慢慢来Its high time that sb. did/should do sth.sthbe to (do): (something) will definitely happen, or it must happen 不可防止要发生或必须发生。Eg: They said goodbye, little knowing that they were never to meet again. 他们彼此说了再见 ,几乎不知道再也不可能见面了。She is to be honored fo

7、r this great work. 她一定会因这部著作而获得荣誉。归纳拓展be to do sth. 用法 1)表按方案或安排 ,如：The Queen is to visit Japan in a weeks time 2) “命运,将来必然要发生的事, 译作“注定。 Eg:They said goodbye, little knowing they were never to meet again. 3) 表示“应该/ “义务 ,相当于should, must, have to . 如：You are to report to the police. 4) 用于否认句 ,表示“禁止 ,相

8、当于mustnt。Eg: You are not to smoke in the reading-room5 )表示“想 ,打算 ,相当于intend, want。Eg: If we are to be there soon, well have to go now. 6表示可能性,相当于can, may如: Such books are to be found in the library.by doing 用于说明做某事的手段 ,方式。(回归课本P26) They produced young generally by laying eggs. 它们一般是通过孵蛋而繁衍后代的。Eg: I

9、dont think she can help him by just giving him money. 我认为她光靠给钱是帮不了他的。He used to make his living by painting. 他以前是靠画画为生。prevent from doing 阻止某人做某事。(回归课本P26)They are putting too much carbon dioxide into the atmosphere, which prevents heat from escaping from the earth into space.他们把过多的二氧化碳释放到大气层中 ,这使得地

10、球上的热不能释放到太空中去。Eg: His heart trouble did not prevent him (from) going to class the next day. 他的心脏病痛没能阻止他第二天去上课。Nothing can prevent their plans (from) being carried out. 归纳拓展 同义句型stop from doing keep from doing allow 允许 (回归课本P26) allowed the earth to dissolve harmful gases and acids into the oceans an

11、d seas. 它使地球把有害气体溶解在海洋里。allow sb to do 允许某人做某事。Eg：Her parents wont allow her to stay out later than 11:00 in the evening. Please allow me to explain that I did not have any idea about his arrangement.但要注意：“准许做某事应当是allow doing 不是allow to do。如：Eg：They shouldnt allow parking in this street. Its too nar

12、row. Walking on the grass is not allowed. 不许踩踏草坪。 归纳拓展 let, permit, allowlet允许 ,让 ,常用于口语中 ,一般不用于被动语态。后接不带to的不定式作宾补。permit v. & allow v. 在许多情况下二者可以通用, 但：permit更正式、积极 ,多指上级对下级或长辈对晚辈的准许,语气较强；有“主动许可、正式批准之意。词义较强allow偏重听任或默许 ,多指听任或不管教某人做某事。有并不反对或不加阻止的含义 ,词义较弱。常用句型allow/permit sb. to do sth. be allowed

13、/permitted to do sth. allow/permit doing sth. eg：The nurse allowed him to remain there, though it was not permitted.now that 既然(回归课本P31)Walking does need a bit of practice now that gravity has changed.Now (that)/ seeing (that)/considering (that) / in that鉴于某个事实 ,原因是 ,用法与since接近not thatbut that 不是因为

14、,而是因为; on ground(s) that 理由是归纳拓展 区分 now that, because, since, as, for1)Because 直接的原因 ,有较强的因果关系。(2)As 由于 ,比because 弱。(3)now that“既然；由于that可省略 ,强度更弱 (4)since 既然 ,表既成的事实 ,可与now that互换。 (5) for 因为,并列连词,前面用逗号与主句隔开 ,补充说明原因。break out 突发；爆发。(回归课本P31)We watched, amazed as fire broke out on the outside of the

15、 spaceship as the earths gravity increased.归纳拓展break up 关系的破裂 ,打碎；解散；放假 break down (机器的故障；(精神、身体)崩溃；(谈判 ,方案)失败break off 停止 ,中断 break in 闯入；插话 break into 强行进入某处；突然开始(大笑、欢呼等)break through 突破；强行穿过 break away from.脱离考点/易错点2 重点句子分析【教材原句】What it was to become was a mystery until between 4.5 and 3.8 billio

16、n years ago when the dust began to slowly combine into a ball moving around the sun. P25随后它会变成什么没人能知道 ,知道38-45亿年前 ,这团尘埃才慢慢地形成一个固体的球状物。【句法分析】1、 此处what it was to became 是主语从句 , 其中what既引导主语从句 ,又在从句中做become的宾语。untila solid globe 是until 引导的时间状语；在该时间状语中 , when the dust settled into a solid globes 是定语从句 ,修

17、饰between 4.5 and 3.8 billion years ago。2、 was to become 所用的结构是： be to do , 表示将要发生的事情。【教材原句】The earth became so violent that it was not clear whether the shape would last or not. 地球变得剧烈动乱 ,不知道这个固体形状是否会继续存在下去。【句法分析】1、 句中it是形式主语 ,代替whether引导的主语从句。2、 需要注意的是 ,表示“是否时 ,引导主语从句只用whether ,不可用if。可单用whether ,也可

18、用whether or。Eg：It is not clear whether the US will withdraw its troops from Iraq next year. = Whether the US withdraw its troops from Iraq next year is not clear. It is still a question whether they will come or not. = Whether they will come or not is still a question.【教材原句】 What is even more import

19、ant is that as the earth cooled down, water began to appear on its surface.更为重要的是 ,地球冷却了下来 ,地球外表就开始出现了水。 【句法分析】1、 句中What is even more important 是主语从句；that as 是由 that引导的表语从句。2、 as the earth cooled down在表语从句中做时间状语。3、 cool down 在此次是 “冷却下来。Eg: The hot metal contracts as it cools down.4、 cool sb dow

20、n ,作及物或不及物动词短语 ,表示“使某人冷静、镇静或降低热情。Eg： Mother gave the little girl some chocolate to calm her down.【教材原句】 Others, called amphibians, were able to live on land as well as in the water. 另外一些叫两栖动物 ,它们既能在陆上生活 ,也能在海里生存。【句法分析】1、 called amphibians, 是一个过去分词短语 ,作后置定语修饰others。此处用逗号隔开 ,相当于一个非限制性定语从句。过去分词作后置定语常以两

21、种形式出现。1） 位于被修饰词之后 ,前后有逗号隔开。A pop group, called S.H.E, is coming to give a concert. 2) 位于被修饰词之后 ,无逗号隔开。 An explorer sent by China has landed on Mars.2、 as well as是一个连词词组 ,用于连接两个相同的成分 ,着重点在前者。The robot dances as well as sings.【教材原句】 Why they suddenly disappeared still remains a mystery.它们为什么突然灭绝至今仍然是个

22、谜。【句法分析】1、 Why they suddenly disappeared 是why引导的主语从句。2、 remain在此是系动词 ,意为“继续存在 ,留下。此词无被动语态 ,不用于进行时。【教材原句】 So whether life will continue on the earth for millions of years to come will depend on whether this problem can be solved.所以 ,在未来的数百万年中 ,生命能否在地球上延续取决于这个问题能否被解决。【句法分析】1、 这是一个复合句 ,主语和宾语是分别由两个wheth

23、er引导的名词性从句组成的。2、 millions of year 意为“数百万年。3、 years to come 意为“未来数年 , in the years to come在未来数年里“ ,当介词用for时 ,动词要用延续性动词 ,for表示延续的时间。4、 depend on 在句中表示“取决于“ ,还可以表示依靠“。介词on可用upon替换。考点/易错点3 语法点学习 主语从句主语从句：在句子中做主语的从句叫做主语从句。主语从句用法：一、由whatwhatever ,whoever等代词引导的主语从句。What they are after is money. 他们追求的是金钱。Wh

24、atever was said here must be kept secret. 这里说的话都应当保密。二、由连词that引导的主语从句。其中that一般不可省略 ,但假设用it作形式主语 , that从句后置时 ,那么可省略。为防止头重脚轻 ,我们倾向用it开头 ,后接be ,seem等。如果句子是疑问形式 ,就只能用带it的结构。That money doesn't grow on trees should be obvious.金钱不能从树上长出来是显而易见的。It is obviousthatmoney doesn't grow on trees .显而易见 ,金钱是

25、不能从树上长出来的。Has it been announced when the planes are to take off？飞机什么时候起飞宣布了没有？注意：1选用what还是用that引导主语从句要根据关联词在从句中是否担任成分而定。且what以及whatever ,whoever等引导的主语从句一般不用it作形式主语。What he said is true.他说的是真的。what在其引导的主语从句中作宾语。That China is a great socialist country is well known.=Its well known that众所周知 ,中国是一个伟大的社会

26、主义国家。that在其引导的主语从句中不作任何成分 ,也无词义 ,只起连接作用。2it引导的强调句与it作形式主语的复合句不可混淆。it引导的强调句是用来对句中某一成分加以强调 ,其结构为：“It is或was+强调局部+that或who强调句去掉It is或wasthat或who框架后 ,剩余局部为一个完整的句子。It was I that(who) met Mary in the street yesterday. (强调主语)3常见的用it作形式主语的复合句结构：*It is+形容词necessary ,strange ,important ,wonderful ,possible ,l

27、ikely ,等+that从句 ,从句中常用虚拟语气。Its necessary that he write something in English.他用英语写点东西是必要的。Its strange that she did not go to school yesterday.奇怪的是她昨天没去上学。*It is+名词a fact ,a pity ,no wonder ,good news ,等+that从句It's a pity that she should have said so.真遗憾她竟然会这么说。*It is+过去分词said ,reported ,decided ,

28、unknown等+that从句Its said that our English teacher will go abroad next week.据说我们英语老师下周要去出国。*It +不及物动词seems ,appears ,happens , matters等+that从句It seems that she is in great need of help.看来她急帮助。4主语为从句时 ,一般要用单数谓语动词形式；但如果引导的从句作主语、代表复数概念常可从表语上看出时 ,谓语动词那么常用复数形式：What we need is water. 我们需要的是水。What we need ar

29、e useful books. 我们需要的是有用的书。三、由连接代词或连接副词或if, whether引导的主语从句。When they will come hasn't been made public.他们什么时候回来还没有宣布。Whether Ill attend the meeting hasnt been decided.=It hasnt been decided whether(if) Ill attend the meeting.我是否参加会议还未决定。四、例题精析【例题1】 【题干】_surprised me most was the sudden change of

30、 his attitude.A. ThatB. WhatC. WhichD. It【答案】B【解析】此题考查主语从句。从句意上分析,本句应是“最让我吃惊的事情,而what一词可表示the thing that (surprised me most),其他选项语法不通。【例题2】 【题干】What shall we use for power when all the oil in the world has _? A. given outB. put onC. hold upD. used up 【答案】A 【解析】given out意为“耗尽,用尽,无被动式；put on意为“穿上；hold

31、 up意为“堵塞；used up意为“用尽,主语为物时,需用被动式。【例题3】 【题干】The head office of the bank is in Beijing, but it has _ all over the country.A. companiesB. branchesC. organizationsD. businesses 【答案】B 【解析】branches意为“分支,分公司,正合题意。 五、课堂运用【根底】1、It worried Mary a bit _ she would pass the college entrance examination.A. wheth

32、erB. ifC. thatD. how 【答案】A【解析】此题中,it是形式主语,要求选出引导主语从句的连词。如果选择that, Mary就不必着急了；句意为“使她感到忧虑的是,她是否能够通过考试,所以,D项排除。if不能引导主语从句,也排除。 2、I was still sleeping when the fire _,and then it spread quickly.A. broke outB. put outC. came outD. got out【答案】A 【解析】题意为“火灾发生的时候,我正在睡觉。A项意为“发生；B项意为“扑灭；C项意为“开花、出版；D项意为“出来

33、。3、The meeting was held in a lively _ and everybody felt free to share his ideas.Aatmosphere BweatherCsituation Dphenomenon【答案】A【解析】考查名词词义辨析。atmosphere气氛 ,气氛；weather 天气；situation情形 ,状况；phenomenon现象。【稳固】1、_well go camping tomorrow depends on the weather.A. IfB. WhetherC. ThatD. Where【答案】B 【解析】B、C、D三项

34、均可引导主语从句,但是本句含有疑问的意思,因此that排除；根据句意,是否camping和天气关系更为密切,所以where排除；if虽也可表示“是否,但其不能引导主语从句,也排除。2、Sarah hopes to become a friend of _shares her interests. A. anyoneB. whoeverC. whomeverD. no matter who 【答案】B 【解析】whoever在句中起双重作用,既作介词of的宾语,也作从句的主语；whomever不能在从句中作主语；no matter who只能引导状语从句。3、Newly­born babies are good sleepers. The amount of their sleep is _ that of adults.Aseveral times larger than Ba few times the size ofCa