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单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,2018/11/23 Friday,#,Discovering useful structures,What part does the underlined part serve as in each sentence,A tree has fallen across the road.,You are a student.,To find your way can be a problem.,Smoking is bad for you.,主语从句Noun Clauses as the Subject,定义：,用作主语的从句叫主语从句，它是名词性从句之一。引导主语从句的连接词有：连词,that, whether,；连接代词,who, what,和,which,；连接副词,when, where, how,和,why,。,【例句呈现】,观察以下例句，指出其中所包含的主语从句及引导词:,1. What is needed for a long trip is careful preparation.,该句中主语从句是 _，引导词为 _。,What is needed for a,what,long trip,2. That Jay Zhou will come to my city excites everybody.,该句中主语从句是,_,_,，引导词为,_,。,3. Whether we will travel abroad or not has not been decided.,该句中主语从句是,_,_,，引导词为,_,。,That Jay Zhou will,Whether we will,come to my city,that,travel abroad or not,whether,4. Whoever knows the secret mustnt tell others.,该句中主语从句是,_,_,，引导词为,_,。,5. It remains a puzzle why dinosaurs died out suddenly long time ago.,该句中主语从句是,_,_,，引导词为,_,。,Whoever knows the,whoever,why dinosaurs died,why,secret,out suddenly long time ago,注意: 上述例句第5句中的主语从句似乎比较隐蔽,但有时为了使句子构造平衡, 防止 “头重脚轻, 常用 it 作形式主语, 而把从句放在后面。 例如:,It is a pity that she has made such a mistake.,她犯了这样一个错误, 真是遗憾。,现将常见的由it作形式主语的句型总结如下：,1. It is + n. + that从句,2. It is + adj. + that从句，常见此类形容词有：important, necessary, clear, certain, natural, strange, obvious, likely, impossible, possible等,主语从句应使用虚拟语气, 谓语动词用“should + 动词原形的形式, should有时有感情色彩。,3. It+特殊动词+that 从句,It seems / appears . that .,似乎,It happened (to sb.) that .,某人碰巧,4. It + be + 过去分词 + 主语从句,It is said / reported / believed / suggested / known / proved that .,It is a pity,that you should have made such a careless mistake,.,It is not clear,how the accident happened,.,It happened,that I was out that day,.,It is reported,that more than thirty deaths were caused in the accident,.,【要点精讲】,1. what与that引导主语从句,观察以下例句，试着翻译例句并总结其规律。,(1) What you lack is self-confidence.,译为：_,你所缺乏的是自信。,(2) That more and more students are admitted into universities is true.,译为：,_,_,(3) What is needed for the program is more wisdom.,译为：,_,这个工程所需要的是更多的智慧。,越来越多的学生将被大学录取的消息是真实的。,从上面例句可以看出，that引导主语从句时，在句中具有“两不原那么：,一、不作句子成分；,二、没有实际意义。,当它引导的主语从句置于句首时，that不能省略；如果用it作形式主语，而把主语从句放在句末时， that可以省略。,而what引导的从句那么恰恰相反，what在从句中的作用为：,一、作句子成分；,二、除了起到引导从句的作用外还,要承担具体的意义。,2. whether,与,if,引导主语从句,如果主语从句置于句首，不能用,if,引导，此时，需用,whether,。但如果用,it,作形式主语，而把主语从句放在句末时，也可以用,if,引导。,【稳固练习】,用whether或if填空。,(1) It doesnt matter _ he will come or not.,(2) _ well go camping tomorrow depends on the weather.,(3) It was doubtful _ Tom really saw Sharon.,(4) _ Tom really saw Sharon was doubtful.,whether / if,Whether,whether / if,Whether,3. 其它引导词,连接代词who, which, whom, whose有各自的具体意义，起连接作用，同时在从句中充当主语、宾语、表语、定语等；whoever, whatever, whichever在意义上更为强调，常译为“无论；连接副词when, where, why, how等也有各自的意义，起连接作用，并在从句中作状语。,【常见错误展示】,以下各句均有一处错误，请改正并分析错误的原因。,1. Light travels faster than sound is common knowledge.,That,that,虽无词义但引导主语从句位于句首时不能省略。,if, whether都可表示“是否, 但if不能引导位于主句之前的主语从句，它可以引导位于主句之后带有形式主语it的主语从句。,2. If shes coming or not doesnt matter much.,Whether,3. That the professor said is of great importance.,4. Where will the trees be planted has,not been decided.,What,that引导主语从句时无词义。What the professor said表示“教授所说的。,将,will,置于,trees,之后。主语从句要用陈述句语序。,5. No matter who breaks the rule will be punished.,6. When and where the meeting will be held still remain a question.,引导让步状语从句时二者可互换，但引导名词性从句时只能用,whoever,。,Whoever,主语从句表示单一概念时，谓语要用单数形式。,remains,7. What were your problems a year ago has now become mine.,8. It was requested that everyone,made a speech at the meeting.,has,要改为,have,。主语从句表示复数概念时，谓语要用复数形式。,have,在“It is requested / ordered / suggested + that从句中，从句要用虚拟语气，即谓语用“should + 动词原形，should可省略。,(should) make,1,Find all the sentences where noun clauses are used as the subject and underline them. Then translate them into Chinese.,What it was to become was uncertain,until between 4. 5 and 3. 8 billion years,ago when the dust settled into a solid,globe.,地球会变成什么样子, 直到45亿至38,亿年前这个云团变成一个固体的球状物,才确定下来。,2) 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。,3) What is even more important is that as the earth cooled down, water began to appear on its surface.更重要的是, 随着地球的冷却, 地球的外表就开场出现了水。,4) It was not immediately obvious that water was to be fundamental to the development of life.水对于生命的开展会起关键作用, 这一点在当时并不明显。,5) What many scientists believe is that the continued presence of water allowed the earth to dissolve harmful gases and 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。,6) Why they suddenly disappeared still remains a mystery.,为什么他们突然消失了,至今还是个谜。,7) 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得到解决。,2 Rewrite the following sentences with noun clauses as the subject.,1. His discovery has not yet been proved.,2. Do the other astronomers accept his,ideas It remains a question.,What has not yet been proved is his discovery.,Whether the other astronomers accept his ideas remains a question.,3. The first appearance of life on earth is,still a mystery to scientists.,4. Why is the earth becoming warmer It,is an important topic for research.,How life first appeared on earth is still a mystery to scientists.,Why the earth is becoming warmer is an important topic for research.,5. Stephen Hawking at 65 experienced zero gravity during a flight. It amazed everybody.,6. Pluto is no longer considered a planet in,our solar system. What a surprise!,It amazed everybody that Stephen Hawking at 65 experienced zero gravity during a flight.,It is a surprise that Pluto is no longer considered a planet in our solar system.,3,Read the following passage and complete it with the suitable clauses below. Tell which is a subject clause and which is an object clause .,_ is not only a,question which interests biologists and,geologists. It is a favorite topic for discussion,for physicists and astronomers. They would,like to know _,because this may help them find ways to solve,the problem of global warming.,How dinosaurs disappeared,why dinosaurs became extinct,Some scientists believe _,_,_.,_is uncertain, but,water and food supply decreased and so the,dinosaurs gradually died out. However, the,mammals survived. Other scientists believe,_,_.,became hot and dry dozens of millions of years ago,How the climate changed,that the earth slowly,that comet crashed into the earth long ago and caused the disappearance,As a result of this event, a great dust cloud,formed in the sky blocking out the sunlight.,Without sunlight, most plants soon died and,so many dinosaur species became extinct.,Since the ice age, the climate of the earth has,not changed very much. However,_,is a concern for everybody on earth.,whether the climate will change again,
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