高中英语 Unit 4 Astronomy the science of the stars（第6课时）导学案新人教必修3

1、Unit 4 Astronomy the science of the stars第6课时第17周周三Teaching Goals:1. To get Ss to better understand the text.2. To help Ss the master the usages of important words and expression3. To get Ss to analyze the difficult sentences of the text.Teaching Procedures:Step I Read and find out the difficulties

2、Divide Ss into groups, ask them to read in groups and find out the difficult expressions and sentences.Step II Explanation of difficulties Ask students to list out their difficulties on blackboard. By discussing, students can solve some of them. Analyze the difficulties below:1. What it was to becom

3、e was uncertain until between 4.5 and 3.8 billion years ago when the dust settled into a solid globe. 随后它会变成什么没人能知道，直到38-45亿年前，这团尘埃才慢慢地形成一个固体的球状物。【分析】 a. 此复合句的主句为What it was to become was uncertain；从句为_引导 的定语从句。when b. 主句中包含一个由what引导的主语从句What it was to become。c. until是介词，与其前带否定前缀的形容词uncertain构成not .

4、 until句式，表示“到才，在之前”，引导between 4.5 and 3.8 billion years ago作时间状语。 这句话还可以这样表述：Nobody knew what the cloud of dust would become before it turned into a solid globe between 4.5 and 3.8 billion years ago.2. The earth became so violent that it was not clear whether the shape would last or not. a. 此复合句的主句为

5、The earth became so violent；从句为_引导的结果状语从句。thatb. so . that . 如此以致，其中that可以省略。c. 结果状语从句中包含一个由whether引导的主语从句，_是形式主语。it这句话还可以这样表述：People didnt know whether the solid globe would keep the shape or not, because the earth didnt stop exploding.3. They were in time to produce carbon, ., which were to make t

6、he earths atmosphere. in time: sooner or later; eventuallye.g. Ill see him in time. in time (for sth. /to do sth.): not latee.g. She will be back in time to prepare dinner.与time相关的短语: in no time 立刻, 马上 at times 有时 at a time 每次; 依次 once upon a time 从前 on time 按时; 准时 at one time 从前 for the time being

7、暂时 from time to time 不时地 atmosphere意为“大气，气氛等”。e.g. There was an atmosphere of violence and insecurity. 他们之间以前有种相互信任的气氛。4. What is even more important is that as the earth cooled down, water began to appear on its surface. 【分析】a. 本句的结构是：主语从句（What is even more important）+ 系动词（is）+ 表语从句（that as the ear

8、th . on its surface.）b. 表语从句中含有一个由_引导的时间状语从句。这句话还可以这样表述：Water began to appear on the earth because it cooled down, and this is more important.5. This produced a chain reaction, which made it possible for life to develop.【考点】it作形式宾语，真正宾语常为不定式或从句。【考例1】We feel _ our duty to make our country a better pl

9、ace. AA. it B. this C. that D. one【考例2】Why dont you bring _ to his attention that youre too ill to work on?BA. that B. it C. his D. him【点拨】都选it。都考查it作形式宾语。考例1中，it指代to make our country a better place；考例2中，it指代 _。that youre too ill to work on6. They produced young generally by laying eggs.lay-laid-lai

10、d-laying 放, 把.放在.; 产卵e.g. He laid his books on the desk.注意: lay (laid; laid; laying) 放置; 产卵 lie (lay; lain; lying) 躺; 位于 lie (lied; lied; lying) 说谎 7. , because they gave birth to young baby animals . 【寓词于境】仔细阅读下列句子，并试着总结give birth to的含义及用法。1) Mrs. White gave birth to a fine healthy baby in her late

11、 thirties.2) Mary gave birth to a healthy baby girl.3) It was this event that gave birth to the peace movement. 【归纳】 give birth to后可直接跟名词，意为“_” （句1和句2），也可意为“_”（句3）。分娩 产生【拓展】at birth 出生时 since / from birth 自出生后 date of birth 出生日期8. They are putting too much carbon dioxide into the atmosphere, which p

12、revents heat from escaping from the earth into space.他们把太多的二氧化碳释放到大气层中, 这就使得热量不能从地球上散发到太空中去。阅读下列句子, 注意prevent . from的意思和用法。1) There was nothing to prevent her from doing so.2) We must prevent the water from being polluted.3) The emperor ordered his porters to prevent the speaker entering the building. 归纳 prevent . from的意思是 _。from后多跟动词-ing形式(句1、句2