人教版高一英语必修三Unit 4 Astronomy: the science of the stars辅导材料

主语从句 【语境展示】 观察下面句子，并试着归纳主语从句的用法要点。 1. That he had finished writing the composition in such a short time surprised us all. 2. Whether the plan is to be carried out still needs to be discussed. 3. Who will go to the energy conference is not important. 4. What I wanted was a few days' rest. 5. Which hotel he is staying at is unknown to us.? 6. When the sports meeting will be held has not been decided yet. 7. Where we should leave the garbage is a problem. 8. Why he isn't here today is a mystery. 9. How the man died puzzled us all. 【自我归纳】 在复合句中，担任主语的从句叫主语从句（句1-句9）。引导主语从句的词有：连词that, whether（句1、句2）；连接代词who, what, which （句3-句5）；连接副词when, where, why, how（句6-句9）等。 一、由连词that, whether引导的主语从句 ?????? 1. that引导主语从句时，无实际意义，只起连接作用，不充当任何句子成分，当它引导的主语从句置于句首时，that不能省略（句1）。 ?????? 2. whether意为“_____”，不可以省略（句2）。 二、由连接代词who, what, which引导的主语从句 ?????? 连接代词who, what, which引导主语从句时，在从句中充当主语、宾语或_____等（句3-句5）。 三、由连接副词when, where, why, how引导的主语从句 ?????? 连接副词when, where, why, how引导主语从句时，在从句中充当状语（句6-句9）。 【拓展】 当主语较长时，常用it作形式主语，而将主语从句放在句末。如： It is known to all that light travels in straight lines. It was clear enough what he meant. It has not been announced when the plane is to take off. 常见的由it作形式主语的句型如下： ①It + be +名词+从句。常用于此句型的名词有：fact, rule, pleasure, truth, pity, mystery等。如： It is a fact that English is being accepted as an international language. It is a pity that you can't swim. It was a mystery how the thief got in. ②It + be +形容词+从句。常用于此句型的形容词有：true, important, strange, necessary, clear, certain等。如： It is true that the earth is round. It is strange that he knows nothing about it. It was not clear to me why he behaved like that. ③It +动词+从句。常用于此句型的动词有：seem, appear, happen, follow等。如： It seems that you're right. It happened that Mary wasn't at home that day. ④It + be +过去分词+从句。常用于此句型的过去分词有：known, said, proved, reported, suggested等。如： Is it known where he went? It's said that he was a spy during the war. 注意： 1. that引导的主语从句置于句首时，that不能省略。但是如果用it作形式主语，而把主语从句放在句末时，that可以省略。如： That your pictures should surprise them was quite natural. It was quite natural (that) your pictures should surprise them. 2. 如果主语从句置于句首，则不能用if引导，而用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。如： Whether Tom really saw Sharon was doubtful.? It was doubtful whether / if Tom really saw Sharon. 【即学即练】 用适当的连接词完成下面短文。 I live on the top floor of an apartment block. Just across the road is a bakery. 1. _____ the bakery was built was unknown to me, but seen from its look, it must have a history of over 100 year ... ...