人教版高一英语必修三Unit 4 Astronomy: the science of the stars Grammar课件（44张）

课件44张PPT。Unit 4Unit 4 Astronomy: the science of the starsTo learn the noun clauses as the subjectWhat is subject?a noun, noun phrase or pronoun representing the person or thing that performs the action of the verb, about which something is stated or, in a passive sentence, that is affected by the action of the verbI sat down.The house is very old.The tree was blown down in the storm.①②③David arrived last night. Who is speaking, please? Two will be enough. Looking up all the new words in the dictionary took him a lot of time. To translate this ideal into reality needs hard work. How to do well is an important question. What has happened proves that our policy is right. Underline the subjects in the following sentences. n. pron. num. to do v.-ingphrasesentencesubject clause Find all the examples in the reading passage where noun clauses are used as the subject.()()()()(()()())()()通过发现练习, 我们已经对本课的语法内容有了一定的了解。下面就进一步选择讲解该语法项的重难点。 在句子中起名词作用的句子叫名词性从句。名词性从句的功能相当于名词词组，它在复合句中能担任主语、宾语、表语、同位语、介词宾语等，因此根据它在句中不同的语法功能，名词从句又可分别称为主语从句、宾语从句、表语从句和同位语从句。主语从句在复合句中作句子的主语。引导主语从句的词有： 从属连词: that, whether, if； 连接代词: who, whoever, whom, what, whatever, whose, which； 连接副词: when, where, how, why等。观察下列例句，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 whatlong trip2. 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 willWhether we willcome to my city thattravel abroad or notwhether4. Whoever knows the secret mustn’t 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 whoeverwhy dinosaurs diedwhysecretout suddenly long time ago【观察总结】 通过分析上面例句，同学们可能会发现上面第5句中的主语从句似乎比较隐蔽。其实，这也是主语从句的一种呈现方式，即：当一个句子主语过长时，可以用it作形式主语，而把真正的主语或主语从句后移至句子末尾，以保持句子的平衡。注意观察下列例句中的划线部分：It is not clear how the accident happened. It is not hard to understand why he did so at that time. It is a pity that you should have made such a careless mistake. It is reported that more than thirty deaths were caused in the accident.不难看出，虽然上面例句中都用it作形式主语，但句子结构却不尽相同。现将常见的由it作形式主语的句型总结如下： 1. It be + n. + that从句 2. It be + adj. + that从句，常见此类形容 词有：important, necessary, clear, certain, natural, strange, obvious, likely, impossible, possible等。3. It+不及物动词+that从句 It seems / appears ... that ... 似乎…… It happened (to ... ...