8.时间的脚印PPT

时间是什么？,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,时间是物质存在的客观形式，无处不在，与每个人密切相关，但它看不到、触不着。,记录时间的工具,还有什么可以记录时间的更替？,8,时间的脚印,了解岩石记录时间（历史）的相关知识，掌握本文说明顺序中的逻辑顺序。,（重点）,明确说明对象，理清文章思路；体会本文生动有趣的语言。,（难点）,认识岩石记录时间的功能，培养学生的探索意识和科学精神。,（重点）,学习目标,陶世龙,（,1929,），四川安岳县人，我国著名科普作家。,代表作品有,打开地下宝库的钥匙,揭开大地的秘密,地球的画像,火山和地震,多变的地球,等科普读物。,作者简介,本文选自,时间的脚印,（江苏教育出版社,1999,年版）。科普作家陶世龙毕业于北京大学地质系，参加工作后长期与地质学科打交道，在国家推动科学普及和科学大众化的倡导下，作者致力于科普写作，尤其是针对青少年的科普作品较多。这篇科普文章以记录时间的方式为切入点，向我们介绍了有关岩石的丰富而有趣的科学知识。,背景链接,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,踪,迹（ ）,腐,蚀,（ ）,浑,浊,（ ）,山,麓,（ ）,粗,糙,（ ）,龟,裂（ ）,帷,幕（ ）,刨,刮（ ） 沟,壑,（ ）,楔,形（ ） 钟,鼎,文（ ） 海,枯,石烂（ ）,zn,jn,co,sh,w,i,p,o,h,l,zhu,xi,dn,k,字词学习,词语解释,腐蚀：,通过化学作用，使物体逐渐消损破坏；人在坏的思想、行为、环境等因素影响下逐渐变质堕落。,(,本文用义项,),浑浊：,(,水、空气等,),含有杂质，不清洁、不新鲜。,海枯石烂：,海水枯干，石头粉粹。现多用于形容经历极长的时间，但本文是原意。,龟裂：,裂开许多缝子。,胶结：,半流体干燥后变硬黏结在一起。,钟鼎文：,古代铜器上铸的或刻的文字，通常专指殷周秦汉铜器的文字。,甲骨文：,古代刻在龟甲和兽骨上的文字，内容多是殷人占卜的记录，现在的汉字就是从甲骨文演变下来的。,楔形文字：,公元前三千多年美索不达米亚南部苏马连人创造的文字，笔划像楔子，古代巴比伦人、亚述人、波斯人等都曾使用这种文字。,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,贴小标题：,这些小标题可以归纳一些段落的内容，请将它们写到相应段落的开头。,整体感知,(,理清文章的脉络）,(1,5),“,时间漫谈,”,“,石头的毁灭与新生,”,“,石头上的故事,”,“,读懂记录，造福人类,”,(6,21),(22,29),(30,31),认真读课文，概括各部分大意。,第一部分,由人类记录时间踪迹的方式联想到大自然记录时间的方式，进而,提出,“,岩石是怎样记下时间,”,的疑问，引人思索和探寻。,(1,5),第二部分,从,“,大自然中的各种物质都时时刻刻在运动着,”,这一规律入手，,详尽说明岩石,“,烂,”,与,“,生成,”,的变迁，旨在说明岩石层与层之间的顺序记录了时间的踪迹。,(6,21),状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,第四部分,启发人们探索自然奥秘，说明读懂岩石记录的重大意义。,第三部分,说明岩石为我们记录下的历史痕迹。,(22,29),（,30-31,）,快速通读课文，找一找：文中有些段落只有一句话但起着承上启下的作用。请找出几个这样的例子，并作简要分析。,5,、,7,、,18,、,22,、,24,、,27,1.,岩石是怎样记录下时间的呢？（,5,）,承上启下，由人类记录时间的方式，引出岩石记录时间方式的探寻。,2.,真的有,“,海枯石烂,”,的时候。（,7,）,开启下文，说明岩石,“,毁灭,”,的过程。,3.,经过长期的重压和胶结，那些碎石和泥沙重新形成了岩石。（,18,）,总括上文，总结了岩石,“,毁灭,”,之后再度,“,新生,”,的过程。,4.,岩石保存了远比上面所说的多得多的历史痕迹。（,22,）,承上，收住有关岩石自身解体与新生的话；启下，解读下文有关岩石上的历史痕迹。,5.,从,“,死,”,的石头上，我们看到了地壳的活动。（,24,）,概括评价上一段的叙述内容。,6.,化石是历史的证人，它帮助我们认识地球历史的发展过程。（,24,）,承上文，化石的作用；启下文，说明化石是怎样帮我们认识地球历史的发展过程的。,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,自由读课文，思考：课文主要介绍分析岩石记录时间的奇异功能，为什么不直接进入正题，而要先引用高士其的话？,课文精讲,时间伯伯，,你是最伟大的旅行家，,你从不犹豫你的脚步，,你走过历史的每一个时代。,高士其时间伯伯,引用高士其的话,把时间拟人化，一方面与主题照应，另一方面，通过引用，由生活时间引入地质时间，更切合读者实际生活，吸引读者,。文题,“,时间的脚印,”,实际上是,“,从岩石上，可以看到时间的长短,”,的意思。,自由读,1-5,自然段，,说一说,：,1.,现在的人们是怎样记录时间的？,钟表和日历,2.,中国古代用什么来记录时间？,铜壶滴漏,3.,本文中提到的岩石有什么作用？,它是大自然用来记录时间的。,铜壶滴漏,水从一个铜壶缓缓地滴进另一个铜壶，时间过去了，这个壶里的水空了，那个壶里的水却又多了起来。时间是看不见的，但是我们用水滴记下了逝去的时间。,小知识,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,自由读,6-21,自然段，分组讨论：,1.,岩石的,运动规律,是什么？,被破坏,被搬运、被堆积,重新生成岩石,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,2.,你能根据书上的有关内容概述石烂到新生的过程吗？,岩石,小石子,沙砾、泥土,新岩石,沉淀,重压,胶结,3.,人们是怎样根据岩石来判断时间的？（重点读第,19,自然段）,可从,岩层厚度,、,排列顺序,、,地壳运动,等方面思考。,岩层厚度：,1,米厚（,3000,10000,年）；,排列顺序：最早形成的躺在最下面；,地壳运动：平卧的岩层变得歪斜甚至直立。,自由读,22-29,自然段，分组讨论：,1.,岩石是怎样保存历史痕迹的？,可从,岩石结构,、,石头颜色,、,生物化石,等方面去考虑。,岩石结构,反映地壳的活动,石头颜色,反映远古的气候,生物化石,反映历史的发展,2.,岩石保存了哪些历史的痕迹？,地壳的活动；,气候的变化；,古代生物的状况；,地球历史的发展过程；,自然界转瞬即逝的活动。,说说时间在岩石上留下了哪些,“,脚印,”,，这些,“,脚印,”,是由哪些因素导致的？,因素：炙热的阳光、严寒、霜、雪、风、雨、空气、水和水中的酸类，生物、人类的活动等。,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,3.,人类是怎样根据岩石来认识地球的发展历史的？,根据不同类型的化石去思考。,三叶虫化石,“,寒武纪,”,海洋宽广,大树木化石,“,石炭纪,”,温暖潮湿,长毛兽化石,“,第四纪,”,气候寒冷,三叶虫化石,小知识,细细品味最后一段，说一说：读懂岩石记录有什么重大意义？,不仅可以增加知识，而且可以探寻地下,“,宝藏,”,，更有无穷的大自然奥妙存在。,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,狂风吹来了，洪水冲来了，冰河,爬,来了，碎石、沙砾、泥土被它们带着，开始了旅行。,把,“,爬,”,字改成,“,流,”,字可以吗？为什么？,不好。用,“,爬,”,字，形象生动，而且显出移动的缓慢。,品析语言,在受到重压的时候，有一些物质填充到泥沙中的孔隙里去，就使泥沙,胶结,得更紧密了。,把,“,胶结,”,改成,“,粘合,”,可以吗？为什么？,不可以。用,“,胶结,”,准确地表明了泥沙变成岩石所起的变化。,岩石在最初生成的时候，像书页一样平卧着，一层层地叠在一起，最早形成的,“,躺,”,在最下面。,把,“,躺,”,字改成,“,铺,”,字好吗？为什么？,不好。,“,躺,”,字，与平卧呼应，且形象生动。,1.,课文在说明岩石可以记录时间后，接着写了一段介绍北京故宫,“,铜壶滴漏,”,的内容，这是否偏离了文章的主题？,深入探究,没有偏离主题，原因：增强文章吸引力，使人联想到岩石记录时间的方式也会很有趣；这是一种做铺垫的写法，人类记录时间的方式有如此奇异的，那么大自然记录时间的方式会更奇妙，更具内涵。,2.,从本文的说明顺序和探索意义上谈谈你所获得的启示。,通过本文的学习，我们了解到常见的说明顺序有时间顺序、空间顺序、逻辑顺序。同时我们还知道岩石原来也能记下时间，岩石就是一部无字的史书。其实岂止岩石？大自然中的一事一物，都是一部蕴含深刻内容的史书。陶先生不过是给我们拉开了帷幕的一角而已，我们要不断丰富自己的知识，用自己的智慧和才能去探求大自然的奥秘，来造福人类。,3.,本文向我们介绍了有关岩石的丰富而有趣的科学知识，你由此对科普类文章有了怎样的认识呢？大家讨论讨论，然后踊跃争当中心发言人，谈谈大家的认识。,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,总述自然界各种物质的运动,人类记录时间,时间脚印岩石记录,分说岩石,“,烂掉,”,的原因和过程,岩石层记录时间的踪迹,岩石记录的历史痕迹启发人们探索自然奥秘,分说岩石生成的过程和历时的漫长,时间的脚印,总说岩层与岩层之间的顺序记录时间的踪迹,大自然记录时间,板书设计,本文以充满智慧的笔触，娓娓而谈岩石能够记录时间的脚印的原因，记录的内容和人类读懂大自然这种记录的重大意义，以丰富的实例和富有启发性的语言，引起人们探索自然奥秘的兴趣。,主旨概括,1.,条理清晰，有逻辑性。,文章第二部分，首先总说自然界各种物质的运动。然后分说岩石的原因和过程。接下来分说岩石生成的过程和历时的漫长。最后总说岩层与岩层之间的顺序记录时间的踪迹。层次分明，条理清晰。,写作借鉴,2.,语言生动形象。,本文语言生动形象，把时间拟人化，既给人以知识，又给人一种亲切感。例如，作者采用了排比句式，如,“,炎热的阳光烘烤着它，严寒的霜雪冷冻着它，风吹着它，雨打着它,”,说明了岩石遭受到来自多方面的破坏。再如，采用打比方的说明方法，使说明生动、形象，如,“,如果大量的水结成了冰，刨刮着所遇到一些石头,”,。,拓展延伸,少壮不努力，老大徒伤悲。,一寸光阴一寸金，寸金难买寸光阴。,放弃时间的人，时间也放弃他。,时间就像海绵里的水，只要愿挤，总还是有的。,莫等闲，白了少年头，空悲切！,逝者如斯夫，不舍昼夜。,人们对时间感受的名言：,找一找：文中运用了哪些说明方法，试举例说明。,课外阅读有关科普读物。,课后作业,