第四讲Unit 4 Natural disasters.学习目标1. Unit 4重点单词、短语2. it作形式主语的用法.重点、难点分析 1、 What other natural disasters can you think of? 你还能想到其他的自然灾害？think of 想起，想到，认为辨析：think of, think about与think over（1）thinkof想出，记起，考虑Eg: Whothoughtoftheidea？ 谁想出的这个主意？（2）thinkabout思考，考虑 Eg: Illthinkaboutyoursuggestion，andgiveyouananswertomorrow我要考虑一下你的建议，明天给你答复。（3）thinkover意为“仔细考虑”。 Eg: Thinkover，andyoullfindaway 仔细考虑一下，你就会有办法的。【拓展】What do you think of? 是固定句型，意为“你觉得怎么样？”，相当于“How do you like?”。Eg: What do you think of the film? = How do you like the film?2、Because he is interested in the North and South Poles. 因为他对南北极感兴趣。be interested in 对.感兴趣， 后面跟名词或者动名词作宾语。The boy is interested in science.They are interested in playing computer games.辨析： interested与interestingInteresting表示事物本身具有使人产生兴趣之处；如The cat is interesting.而interested表示某人对某事感兴趣；如I am interested in the book bought yesterday.3、What would happen if our city was badly flooded? 如果我们的城市严重淹水，将会发生什么事情？happen是不及物动词。happen的用法主要有以下三种：（1）sth.+happen+地点/时间，意为某地/某时发生了某事。Eg：Anaccidenthappenedinthatstreet. 那条街发生了一起事故。Whatshappeningoutside? 外面发生什么事了？（2）sth.+happento+sb.意为某人出了某事(常指不好的事发生在某人身上)。Eg: Acaraccidenthappenedtohimyesterday. 昨天他发生了交通事故。Whathappenedtoyou? (=Whatwaswrong/thematterwithyou?) 你怎么啦？（3）sb.+happen+todosth.意为某人碰巧做某事；或者”It happens + that从句”，意为“碰巧.”Eg: Ihappenedtomeetherinthestreet. 我碰巧在街上遇见她。IthappenedthatIwasoutwhenhecalled. 他来访时我碰巧不在。辨析：happen与take place1). take place 表示“发生、举行、举办”，一般指非偶然性事件的“发生”，即这种事件的发生一定有某种原因或事先的安排。Eg：Great changes have taken place in our hometown during the past ten years. The Olympic Games of 2008 will take place in Beijing. 2). happen作“发生、碰巧”解，一般用于偶然或突发性事件。Eg：What happened to you? I happened to see him on my way home. = It happened that I saw him on my way home.4、Would anyone remain alive? 还有人活着吗？ （1）remain此处作连系动词，意为“一直保持；仍然处于某种状态”，后面可接形容词、名词、动名词ing形式、动词ed形式或介词短语。Eg：Whatever achievements youve made, you should remain modest. 无论你取得多么大的成就，你都该保持谦虚。【拓展】remain stay 都指“继续停留”或“继续保持某种状态、关系或行动。”remain 常可与stay 互换。 1）表示“继续呆在某处”时，应该用不及物动词remain或stayEg：Shall I go or stay? He remained in his seat after all the other students had gone home. 2）表示“继续保持或处于原来的状态”时，可用remain或stayEg： The door stayed closed. 3）表示“暂住、短期停留”时，只能用不及物动词stayEg：He is staying at Hilton Hotel.4）表示“残留、剩下”时，只能用不及物动词remainEg：Not much of the house remained after the fire. 5） remain 强调“继续停留于一处或保持原状态、情况性质而不改变”, stay强调“某人物继续留在原地而不离开Eg：This place remains cool all summer. He stayed to see the end of the game. （2）alive形容词，意为“活着的，在世的”。 Eg: Is the old man alive now?【注意】alive和living都可以表示“活着的”，但alive通常作表语或后置定语；而living修饰人或者物时需要前置。 Eg: All living things need air.5、It covered roads, parks and small houses. 水淹没了道路、公园和小房子。Cover 此处用作及物动词，意为“覆盖；盖上”，常与介词with搭配。cover with 意为“用把盖住”（表示动作）be covered with. 意为“被覆盖”（表示状态） Eg: Please cover the table with a white cloth. The hills are covered with trees.【拓展】cover 还可以用作名词，意为“覆盖物；封面等” Eg：The book needs a new cover.6、Large objects, such as coaches and boats, passed by my window. 大件的物体，例如汽车和轮船，从窗前经过。 pass by 意为“通过；经过”；还可以表示“（时间）逝去；过去”。Eg: I see them pass by my house every day. Three years had passed by before she finally found a suitable job.7、I had to do something. 我必须做点什么！辨析：have to 与must（1）must多表示主观需要或责任感的驱使有必要或有义务去做某事，多译为“必须”，而haveto多表示客观存在的环境所限,即客观要求(无奈)而为之，多译为“不得不干某事”。Eg：Imustcleantheroombecausetherearetoodirty.（无人强迫）因为太脏了，我必须要打扫房间。Wemustbethereontime.（责任感的驱使）我们一定准时到达。Ihavetodomyhomeworknow.（不得不做）我现在不得不做作业。Ihavetoleaveschoolbecausemyfamilyispoornow.（无奈）因为家里穷了，我不得不退学。（2）must没有时态的变化，而haveto有时态的变化。Eg: Damingwashurt.Thedoctorsaidhehadtostayinhospitalforabouttwoweeks.Hisfatherhastogototakecareofhim.WedonthavetogotoschoolonSundays.星期天我们不必上学。（3）must的否定为mustnt，多表示“禁令”。Eg：No!Youmustntturnleft!YoumustturnrightintoTheStrand. 不！你不能向左转！你应该向右转进入到strand中。由must引起的疑问句，肯定回答要用must或haveto，否定回答要用neednt或donthaveto，意思是“不必”；此用法在中考中的单选题中容易出现！Eg: 1）MustIfinishmyhomeworkbeforeeightoclock?我必须要在8点之前完成作业吗?Yes,youmust. 是的，必须。 2）MustIattendthemeeting?我必须要参加这次会议吗？No,youneednt/donthaveto.YoucanaskTomtogoinstead. 不，你不必。你可以让汤姆替你去。7、I tried to call my dad, but the line was dead. 我试图给我爸爸打电话，但是电话线路不通。 （1）try to do sth. 意为“试图/努力做某事”，侧重尽力，为了达到目的而努力；否定形式为try not to do sth.Im trying to learn English well. （2）try doing sth. 意为“试着/尝试做某事”，只是一种新的尝试，不一定付出很大的努力。Lets try knocking at the back door.【拓展】 1）try ones best to do sth. 意为“尽某人最大努力做某事”We should try our best to practice speaking English. 2）try on 意为“试穿”Can I try in on? 3）try 作可数名词，意为“尝试”，常构成have a try，意为“试一试”I cant open the door. Will I have a try?8、