优化课堂2012高一英语精品课件：UNIT 4 SECTION Ⅰ WARMING UP .ppt

1、Unit 4 Astronomy:the science of the starsSection Warming Up&Reading一、根据课文内容，选择最佳答案1.Why was life able to develop on the earth but not on otherplanets?_A.The earth had a solid shape.B.The earth did not have harmful gases in its atmosphere.C.The water stayed on the earth but not on other planets.D.The

2、 earth was not too hot and not too cold.C2.Why was it necessary for plants to grow before animals?_A.Animals needed plants to protect them from the sun.B.Plants provided oxygen for animals to breathe.C.Animals could hide from hunters in forest.D.It was easier for plants to grow.3.Why did dinosaurs d

3、isappear 65 million years ago?_A.Because the earth was too hot for them to live on.B.Because there was no food for them to eat.C.Because the earth exploded at that time.D.It still remains a mystery for us.DB4.Which is the correct order of the following animalsappearance on the earth?_1.shell fishes

4、2.mammals3.reptiles4.insects 5dinosaursA.1,4,3,5,2B1,4,2,3,5C.4,1,3,5,2 D3,4,1,5,25.What problem is caused by human beings?_A.They exist everywhere on the earth.B.They cause global warming.C.They find new methods of growing crops.D.They enjoy hunting and fishing.ABPara.Main idea1A widely accepted(1)

5、_ about the formation ofthe universe2The(2)_ of the earth3The(3)_of water for life4The(4)_of plants and animals on the earth5The(5)_ of humans and their impact on theearth二、阅读课文，然后完成下列表格theoryformationimportancedevelopmentarrival三、课文内容复述According to a widely accepted(1)_ the universebegan with a“Big

6、 Bang”After the“Big Bang”，the earth wasjust a cloud of dust.Between 4.5 and 3.8 billion years ago,the dustsettled into a solid(2)_The earth became so(3)_(violence)and exploded loudly with fire and rock.They were in(4)_ to produce(5)_，nitrogen,water and soon.Water was to be(6)_ to the development of

7、lifeand made the earth dissolve(7)_(harm)gases and acidsinto the oceans and seas.Many millions of years later,the first smalltimecarbonfundamentalharmfultheoryglobeviolentplants began to appear on the surface of the water.They(8)_(multiply)and filled the oceans and seas.Next,green plants began to gr

8、ow on land.They were followed by landanimals,from insects,amphibians to reptiles.After that,some hugeanimals developed and(9)_(exist)on the earth for morethan 140 million years.And then mammals appeared and gave(10)_ to young baby animals and produced milk to feedthem.multipliedexistedbirth四、概括课文大意(

9、约 30 词)提示：文章解释了生命如何在地球上开始。首先，地球爆炸并产生水。因为水的存在，然后植物和动物，包括人类逐渐在地球上出现。(explode;water;plant;animal;human being;exist)The passage explains how life began on the earth.At first,theearth exploded and produced water.And then plants and animalsincluding human beings appeared on the earth gradually becausewate

10、r exists on the earth.However,universe beganaccording to a widely accepted theory,thewith a “Big Bang”that threw matter in alldirections.然而，一种普遍为人们所接受的理论是：宇宙起源于一次大爆炸，这次大爆炸将物质投射到四面八方。1theory n学说；理论典例One theory about the moon is that it is a piece brokenoff the earth.有一种关于月球的理论认为它是从地球分离出的一部分。拓展 in the

11、ory 理论上in practice 实际上运用 完成句子Your plan is good _(理论上),but it doesntwork _(实际上)in theoryin practice2begin with 从开始典例 Mr Hawkings history class often begins with a story.霍金先生的历史课经常以一个故事开始。拓展to begin with to start with 以开始；由作为开头；首先运用 完成句子begins/starts withKnowledge _(开始于)practice._(首先),we have the corr

12、ect leadershipof the Party.To begin/start withHe _ his speech _(以开始)a poem.began/startedwithThe earth became so violent that it was not clear whetherthe shape would last or not.地球变得如此激烈动荡，不知道这个固体形状是否会继续存在下去。3violent adj.猛烈的；激烈的；强暴的典例 The boat sank in a violent storm at sea.船在海上猛烈的风暴中沉没了。They laid vi

13、olent hands on him.他们对他施以暴力。拓展 violence n暴力，强暴；猛烈violently adv.强暴地；猛烈地运用 用 violent 的适当形式填空After running,his heart beats _.Some _ scenes were cut from the film before itcame to show.He was involved in the domestic _.violenceviolentlyviolentThey were in time to produce carbon,nitrogen,watervapour and

14、other gases,which were to make the earthsatmosphere.它们最终产生了碳、氮气、水蒸气和其他多种气体，从而形成了地球的大气层。4in time(for sth./to do sth.)及时；终于典例The car came to a stop just in time to prevent anaccident.汽车及时停下，避免了一场车祸。拓展 on time 准时at a time 每次；一次in time of 在的时候ahead of time 提前at times 有时in no time 立刻，马上at no time 绝不for t

15、he first time 第一次，初次(用作时间状语)运用 用 time 构成的短语填空Please come in one _，not all together.They were just _ for the train.We can ask our teacher for help _ trouble.Everyone may make mistakes _.at a timein timein time ofat timesWater had also appeared on other planets like Mars but,unlike the earth,it had di

16、sappeared later.在像火星这些其他行星上也出现了水，但和地球不同的是，这些水后来都消失了。5unlike prep.不同；不像 adj.不同的；不相似的典例 Unlike his brother,he has a good sense of humor.和他的兄弟不同，他很有幽默感。They are both teachers.Otherwise they are quite unlike.他们俩都是老师。除此之外，他们迥然不同。拓展 like prep.像；如同 v喜欢dislike v不喜欢；讨厌likely adj.可能的 adv.很可能alike adj.相似的，同样的

17、adv.一样地，相似地运用 用 like 的适当形式填空An elder sister is a friend _ any other.In someway,shes _ a mother.She listens to your problems and givesgood advice.alikeHe likes cats but _ dogs.Its _ that they look _ but actually they comefrom different families.likelydislikesunlikelikeWhat many scientists believe is

18、that the continued presenceof water allowed the earth to dissolve harmful gases and acidsinto the oceans and seas.很多科学家相信，由于地球上长期有水存在，使地球得以把有害气体和酸性物质溶解在海洋里。6harmful adj.有害的典例 Smoking is a harmful habit.吸烟是一种有害的习惯。拓展 be harmful todo harm to 对有害harm n&v损害，伤害harmless adj.无害的运用 用 harm 的适当形式填空Large scale

19、 of single crop will be _ to the environmentin the long run.Thats to say,it does _ to our health.The experiment is _ to the animal,so dont worry.harmfulharmlessharmThey laid eggs too and existed on the earth for more than140 million years.它们也下蛋，并在地球上生存了一亿四千多万年。7lay vt.(laid,laid,laying)把放下；摆放；铺(地毯)；

20、产(蛋)；归(罪)于典例 He laid his hand on my shoulder.他把手放在我的肩上。The workers are laying the tracks.工人们在铺设铁轨。Who should we lay the blame on?我们该责备谁？拓展 lay eggs 下蛋lay/put sth.aside 把某物放在一边；积蓄(钱)lay sth.down 把某物放下lay the blame on sb.责备某人lay the table(饭前)在桌上摆好餐具lay emphasis/stress on sth.把重点放在某事上运用 完成句子The bird _(

21、下蛋)in other birds nests.He is a political leader that _(非常强调)individual responsibility.He _ some money _(积蓄)for rainy days.lays great stress/emphasis onlays/putslays eggsaside8exist vi.存在；生存典例 Man cannot exist without air.没有空气人就不能生存。The word doesnt exist in English.英语中不存在这个词。拓展 exist as 作为而存在；以形态存在e

22、xist in 存在于中exist on 靠生存/生活existence n存在；生存existent adj.存在的运用 完成句子 This plant _ only _(存在于)Australia.Can you _(靠 生 存)such a lowsalary?Matter can _(以形态存在)a solid,liquid,or gas.exist asexistsinexist onThese animals were different from all life forms in the past,because they gave birth to young baby an

23、imals and produced milkto feed them.哺乳动物不同于以往所有的生物形式，因为它们能从体内分娩出幼仔并给幼仔哺乳。9give birth to 产生；分娩典例Kangaroos and koala bears give birth to very small andweak young babies.袋鼠和考拉熊产下的幼仔非常幼小虚弱。It is said that James Watts observation of steam issuing from akettle gave birth to the idea of the steam engine.据说

24、，詹姆斯瓦特对水壶蒸汽的观察使他产生了发明蒸汽机的想法。拓展 be born(in)出生(于)at(ones)birth(某人)出生时运用 完成句子She _(生了)a healthy baby last week.The extraordinary experience _(诞生了)his latest novel.His energetic cry was regarded as a good sign to his family_(出生时)gave birth togave birth toat(his)birthThus they have,in their turn,become t

25、he most importantanimals on the planet.于是，他们接着成为这个行星上最重要的动物。10in ones turn 轮到某人；接着典例 He is going to clean the classroom in his turn.轮到他打扫教室卫生了。Now that I have finished buying the materials,Tom,in his turn,should cook.既然我已经买来了材料，接着就该汤姆来做菜了。拓展 in turn 轮流地，依次；反过来，于是by turns 轮流地take turns to do sth.依次/轮

26、流做某事Its ones turn to do sth.轮到某人做某事运用 用 turn 构成的短语的适当形式填空I was on duty _ today.The shop assistants had to have their days off _.I told him the latest news,_，he told me a secret.They _ to look after their sick father.in my turnby turns/in turnin turntook turnsThey are putting too much carbon dioxide

27、into theatmosphere,which prevents heat from escaping from the earthinto space.他们把过多的二氧化碳释放到大气层中，这使得地球上的热不能释放到太空中去。11prevent.from 阻止；制止典例 They prevented the fire from spreading.他们阻止火势蔓延。辨析 prevent.from/keep.from/stop.from这三个短语都有“阻止做某事或阻止某事的发生”之意。prevent.from 和 stop.from 常用于主动语态中，from 可以省略；keep.from 在

28、表示此意时，from 不可以省略。如：I kept the children from going out.I prevented/stopped the children(from)going out.我不让孩子们出去。运用 完成句子We must _(阻止这个计划)being carried out.prevent/stop/keep the plan fromHow life began on earth is one of the biggest puzzles thatscientists found hard to solve.地球上的生命是如何起源的，这是科学家们觉得最难解决的一

29、个谜团。12puzzle n谜；难题 vt.&vi.(使)迷惑；(使)为难典例 Her decision was a puzzle to him.她的决定对他来说是个谜。What puzzles me is why they didnt show up.令我百思不解的是他们为什么没有出现。拓展puzzle over/about sth.对某事苦苦思考puzzle out 苦心思索出(解决办法、答案等)；揣摩出be/feel puzzled about sth.对某事感到迷惑运用 完成句子At last they managed to _(揣摩出)themeaning of the signal

30、s.puzzle outHe _(冥思苦想)an arithmeticproblem this night.puzzled over/aboutMost of us _(对感到迷惑)his sudden missing.were/felt puzzled about本课时单词拓展单词构词法小结violent adj.猛烈的；激烈的；强暴的violence n暴力，强暴；猛烈violently adv.强暴地；猛烈的1._为名词后缀，表示“性质，状态，行为”。如：difference2形容词加后缀_常构成副词。如：smoothly 光滑地。3 _ 为 否 定 前 缀，表示“不”。如：unreal

31、 不真实的。4 _ 为形容词后缀，表示“充 满 的，有 性 质的，有倾向的”。如：beautiful 漂亮的。5_为否定形容词后缀，表示“不，无”。如：careless不细心的。exist vi.存在；生存existence n.存在；生存existent adj.存在的unlike prep.不同；不像adj.不同的；不相似的like prep.像；如同v喜欢harmful adj.有害的harm n&v损害，伤害harmless adj.无害的不同。运用 用所给单词的适当形式填空violence1Some programs on the Internet are full of _pict

32、ures,which lead to the _ at school.(violent)2Hunger _ in many parts of the world.But somepeople in developed countries are not aware of its _.(exist)3_ his quiet and weak brother,Tom _playing football very much.(like)Unlikelikes4In many cases,too much care for children from parentsmight even do _ to

33、 their growth.Some scientists think it_.(harm)harmharmfulexistenceviolentexists1What it was to become was uncertain until between 4.5 and3.8 billion years ago when the dust settled into a solid globe.它会变成什么还没有人知道，直到 3845 亿年前，这团尘埃才慢慢地形成一个固体的球状物。点拨(1)What it was to become 是由 what 引导的主语从句，what 在从句中作 be

34、come 的表语。what 引导主语从句时，可在从句中作主语、宾语或表语。如：What he wants to tell us is not clear.(作宾语)不清楚他要跟我们说什么。What puzzles him is that no one knows that famous actor in thetown.(作主语)使他疑惑的是这个镇上没人认识那个知名演员。(2)be to do 结构在此句中表示不可避免将要发生的动作。如：They were never to meet again.他们注定以后永远不会再见面了。拓展 be to do 结构还有以下用法：(1)表示计划、安排(要做

35、某事)。如：We are to meet at the school gate.我们将在校门口碰头。(2)表示目的。如：The prize was to honour him for his great discoveries.这个奖是为了奖励他的重大发现。(3)表示应该做(某事)。如：What are we to do next？我们下一步该怎么办？运用 完成句子_(他想成为的)is a good Englishteacher.What he wants to beThe shop _(注定要关门),because nocustomers would like to visit it.Her

36、e is a message for you from your head teacher:you_(应该去)to her office after class.is to closeare to go2This produced a chain reaction,which made it possiblefor life to develop.这就产生了一系列的反应，使得生命就有可能开始发展了。点拨make it possible for sb.to do sth.意为“使某人做某事成为可能”，该结构中 make 作使役动词。其中 it 作形式宾语，真正的宾语是后面的不定式复合结构。与 m

37、ake 有相似用法的动词还有 think,find,consider,feel 等；可用于该结构的形容词还有 likely,important,necessary,useless,impossible 等。如：I think it necessary to make a full plan before we start.我认为在我们开始之前制定一个完整的计划是必要的。运用 完成句子The Internet has _(使我们有可能获得更多的信息)from other countries in muchless time.made it possible for us to get more

38、informationThe book _(使我容易学习)English.We _(认为他很可能会离开)before the show starts.makes it easy for me to learnconsider it likely for him to leave1 It was not immediately obvious that water was to befundamental to the development of life.水对于生命的发展会起关键作用，这一点在当时并不明显。结构It is obvious that.(Obviously./It is quit

39、e clear that.)显然仿写 完成句子_(很显然)heis suffering from a bad cold._(显然他没有说实话)yesterday.It is obvious that/It is quite clear that/ObviouslyIt is obvious that/Obviously he didnt tell the truth2 What many scientists believe is that the continuedpresence of water allowed the earth to dissolve harmful gasesand acids into the oceans and seas.很多科学家相信，由于地球上长期有水存在，使地球得以把有害气体和酸性物质溶解在海洋里。结构 主语从句isthat 表语从句仿写 完成句子_(他想告诉我们的是)hewould like to join us anytime._(他 缺 席 的 原 因 是)hewas badly hurt by a car on his way to school.What he wanted to tell us is thatWhy he was absent is that