2014秋高中英语(新人教版必修3)教学课件Unit4-PeriodⅢ.pptVIP

●教学目标 (1)熟记学案中所列出的单词和短语。 (2)通过学案中所给出的重点单词和重点短语的学习，让学生能够正确理解和使用这些单词和短语，能够运用这些词语造句。 (3)通过对语法的教学让学生能够理解并能够运用主语从句。 ●教学地位 语法是学生感到比较难以掌握的东西。让学生正确理解和掌握语法知识是让学生学好英语的关键，所以应给学生创设语境，让学生学会该语法的应用，而不要让学生死记硬背语法条文，应从理解的基础上去运用这些语法。 ●新课导入建议 通过对学生作业的检查导入本堂新课。 1．crash vi. vt.碰撞；坠落；使撞毁 n．(汽车的)撞车事故；(飞机的)失事；突然发出的巨响 Other scientists believe that a comet crashed into the earth long ago and caused the disappearance.(P29) 其他科学家认为很久以前一颗彗星与地球相撞导致恐龙灭绝。 He witnessed a serious car crash today.Two cars crashed into each other and let out a loud crash. 今天他目睹了一起严重的撞车事故。两辆车撞在了一起，发出了很大的爆裂声。 2．climate n．气候，风气，潮 Since the last ice age，the climate of the earth has not changed very much.(P29) 自从上一个冰川世纪以来，地球上的气候变化不大。 I dont like the moral climate in some countries. 有些国家的道德风气我不喜欢。 3．block out挡住(光线)，不去想(回忆) As a result of this event，a great dust cloud formed in the sky blocking out the sunlight.(P29)正因为这一事件，天空中形成了一团巨大的尘云，挡住了阳光。 The heavy curtain blocks out the light. 这厚窗帘把光挡住了。 We found that a big elephant blocked our way. 我们发现一头大象挡住了去路。 The traffic is very heavy and has begun to block up the streets.交通量很大，已经开始把街道阻塞了。 观察下列从Reading中选取的句子，并说出其引导的从句在主句中充当的成分及引导词的功能。 ①What it was to become was uncertain until between 4.5 and 3.8 billion years ago when the dust settled into a solid globe. ②The earth became so violent that it was not clear whether the shape would last or not. ③What is even more important is that as the earth cooled down，water began to appear on its surface. ④It was not immediately obvious that water was to be fundamental to the development of life. ⑤What many scientists believe is that the continued presence of water allowed the earth to dissolve harmful gases and acids into the oceans and seas. [自我总结]　1.引导词what/whether/that引导的从句在句中均可作主语。 名词性从句：主语从句 在复合句中作主语的从句叫做主语从句。 1．主语从句的引导词 Who will do it doesnt matter.(连接代词who在从句中作主语) 谁做这件事都没有关系。 What we need is more water.(连接代词what在从句中作need的宾语) 我们需要的是更多的水。 2．it作形式主语 为保持句子平衡，常把主语从句后置，而用形式主语it代替。it作形式主语时常用于以下句型： It makes no difference where we shall have the m