提供各类精美PPT模板下载
当前位置:首页 > Word文档 >

人教版高中地理必修1第一章第二节太阳对地球的影响教案

  • 新人教版高中英语必修2Unit 3 The Internet-Discovering Useful Structure教案二

    新人教版高中英语必修2Unit 3 The Internet-Discovering Useful Structure教案二

    This teaching period mainly deals with grammar “The Present Perfect Passive Voice.” To begin with, teachers should lead students to revise what they have learned about the Present Perfect Passive Voice. And then, teachers move on to stress more special cases concerning this grammar。This period carries considerable significance to the cultivation of students’ writing competence and lays a solid foundation for the basic appreciation of language beauty. The teacher is expected to enable students to master this period thoroughly and consolidate the knowledge by doing some exercises. 1. Guide students to review the basic usages of the Present Perfect Passive Voice2. Lead students to learn to use some special cases concerning the Present Perfect Passive Voice flexibly.2. Enable students to use the basic phrases structures flexibly.3. Strengthen students’ great interest in grammar learning.1. Help students to appreciate the function of the Present Perfect Passive Voice in a sentence2. Instruct students to write essays using the proper the Present Perfect Passive Voice.观察下列句子特点,总结共同点。1.(教材P28)Much has been written about the wonders of the World Wide Web.2.(教材P28)But the Internet has done much more for people than simply make life more convenient.3.(教材P28)Many people have been helped by the club.4.(教材P28)She no longer feels lonely, and her company has become quite successful.5.(教材P32)Today I thought I’d blog about a question that has been asked many times—how do you stay safe online and avoid bad experiences on the Internet?

  • 新人教版高中英语必修2Unit 3 The Internet-Listening &Speaking&Talking教案二

    新人教版高中英语必修2Unit 3 The Internet-Listening &Speaking&Talking教案二

    From the pictures in the text and the title--- choose the best app, we can know that this part is about how to save money by using apps.Step 2 While-listening1. Laura and Xiao Bo are talking about apps. Listen to their conversation and find out what apps they want.Xiao Bo is looking for a(n) exercise app to help him get in shape.Laura would like an app for getting rich and another that will make her grades better.2. Listen again. Are the sentences true T or false F?1). Both of Xiao Bo's apps keep track of the steps he takes._____2). Xiao Bo's second app can help him make a fitness plan._____3). Laura needs an app that will help her get discounts.______4). Laura needs an app that will add money to her bank account._______F T F T3. Listen once more and tick the sentence you hear. Underline the words used to express predictions, guesses, and beliefs.Predictions, Guesses, and Beliefs________It might help me walk more.________My guess is that it wouldn't work.________I imagine this app would help me get fit faster________I suppose that would be good.________I guess you could save a little with this app.________I suppose there would be some problems, too.________I believe this app could help me get thinner.

  • 新人教版高中英语必修2Unit 3 The Internet-Reading and Thinking教案二

    新人教版高中英语必修2Unit 3 The Internet-Reading and Thinking教案二

    Q5:What's Jan's next goal?Her next goal is to start a charity website to raise money for children in poor countries.Q6:What can we learn from her experiences?We learn that when we go through tough times, we can find help and support from other people online. We learn that we can feel less lonelyStep 5: While reading---rethinkingQ1: What is Jan’s attitude to the Internet ?Thankful/Grateful, because it has changed her and her life.Q2: What writing skills is used in the article ?Examples(Jan’s example, the 59-year-old man’s and the 61-year-old woman’s example)Q3: Can you get the main idea of the article ?The Internet has changed Jan’s life/Jan’s life has been changed by the Internet.Step 6 Post reading---Retell the storyMuch has been written about the wonders of the World Wide Web. There are countless articles (1)telling(tell) us how the Internet has made our lives more convenient. But the Internet has done a lot (2)more(much) for people than simply make life more convenient. People’s lives (3) have been changed(change) by online communities and social networks so far. Take Jan for example, who developed a serious illness that made her (4)stuck(stick) at home with only her computer to keep (5)her(she) company. She joined an online group (6)where she could share problems, support and advice with others. She considered the ability to remove the distance between people as one of the greatest (7)benefits(benefit). She was so inspired (8)that she started an IT club in which many people have been helped. She has started to learn more about how to use the Internet to make society better. Her next goal is to start a charity website to raise money (9)for children in poor countries. Jan’s life has been (10)greatly(great) improved by the Internet.

  • 新人教版高中英语必修2Unit 3 The Internet-Reading for Writing教案二

    新人教版高中英语必修2Unit 3 The Internet-Reading for Writing教案二

    8. However, the more polite you are, the less likely it is you will be attacked. 然而, 你越有礼貌, 你被攻击的可能性就越小。 Step 8 Writing---the articleHow to stay safe in the online chat roomToday I thought I’d blog about a question that has been asked many times--- how do you stay safe online and avoid bad experiences in the online chat room ? I’m not an expert, but many years as a blogger have taught me a thing or two.First of all, there’s the golden rule of the Internet: keep out of what makes you uneasy. Don’t post comments or click on anything. Second, protect your privacy. Don’t give out too much private information like your address, phone numbers, the ID numbers, etc. Third, be polite. If you are polite to others on the Internet, you won’t be attacked in normal situation. Finally, don’t believe in others easily and never meet someone you met online alone. It is very dangerous.Have you had any bad experiences online, or do you have some good advice for staying safe? Post your comments below!Step 9 Pair workExchange drafts with a partner. Use this checklist to help your partner revise his/her draft.1. Does the writer tell the reader what he/she know about the topic ?2. Are the tips and suggestions well organised ?3. Has the writer defined the new words ?4. Does the author include examples, comparison, or explanations ?5. Does the writer end by asking readers to leave comments and/or suggestions ?6. Can you find any grammar or spelling mistakes.Step 6 HomeworkPut up your revised draft in the classroom or read it to your class.

  • 新人教版高中英语必修2Unit 4 History and Traditions-Discovering Useful Structure教案二

    新人教版高中英语必修2Unit 4 History and Traditions-Discovering Useful Structure教案二

    This teaching period mainly deals with grammar: The past participle is used as attributive and objective complement.1. Guide students to review the basic usages of the past participle used as attributive and objective complement.2. Lead students to learn to use some special cases concerning the past participle used as attributive and objective complement flexibly.3. Strengthen students’ great interest in grammar learning.1. Help students to appreciate the function of the past participle used as attributive and objective complement.2. Instruct students to write essays using the past participle used as attributive and objective complement.Step1:温故而知新。Analyze the underlined phrases and then sum up the common usages of the past participles.1.(教材P41)They had castles built(build) all around England, and made changes to the legal system.2.(教材P42)They use the same flag, known(know) as the Union Jack,...3.(教材P42)Judy and I had our car parked(park) in an underground car park near Trafalgar Square, where we could get our car battery charged(charge).Common points: f the past participle used as attributive and objective complement.Step 2:过去分词作定语时的意义1.及物动词的过去分词作定语,在语态上表示被动;在时间上,常表示动作已经发生或完成,有时也不表示时间性。Our teacher watched us doing the experiment and gave us a satisfied smile at last.我们的老师看着我们做实验,最后给了我们一个满意的微笑。The plan put forward at the meeting will be carried out soon.会上提出的计划将很快被执行。2.不及物动词的过去分词作定语,它不表示被动意义,只强调动作完成。Many little kids like gathering fallen leaves in the yard.

  • 新人教版高中英语必修2Unit 5 Music-Reading for Writing教案二

    新人教版高中英语必修2Unit 5 Music-Reading for Writing教案二

    The Internet celebrity Gao Yifeng. Years ago, he owned 5 companies and the staffs over 1,000, but during the economy crisis, he became nothing but debt. He was so worried that his hair became white overnight. There was a time when he wanted to killed himself. But after listening to the song Start Over by Liu Huan, he decided to cheer himself up. He started a steamed bun shop and gradually became a national chain shops. Now he became successful again.Walter Haddon said, “Music is the medicine of a troubled mind.” Music contains such a pleasant and inspiring force. Music gave him courage and bravery. When he listened to the song, it made his spirit fly like a kite in the wind. Music gave him strength and brought him relief. It was the rock I leant on to become strong and to get through those hard times. I hope none of us have to go through the same kind of suffering that he did. At the same time, we all go through various periods when we feel sad or alone. During those times, music can help us in the same way that it helped him. I hope we all will somehow begin to treasure music and make it a part of our life. Thank you for your listening !5.Revise your writing each other.Does he/she explain how music has changed his/her/someone else’s life?Are some of the rhetorical devices included and used properly ?Does he/she talk about how music makes him/her/someone feel?Is the first word in each sentences capitalised?Does he/she use correct punctuation ?

  • 新人教版高中英语必修2Unit 5 Music-Discovering Useful Structures教案二

    新人教版高中英语必修2Unit 5 Music-Discovering Useful Structures教案二

    4. When he got absorbed in his world of music, he felt as if he could “see” the beauty of the world around him, like he had in his previous life.P·P as adverbial: _________________________________________________________________.Function: _______________________________________________________________________.Step 5 Solid Complete the passage with the words in brackets in their correct forms.Well known as a successful band, the Impact members show quite a few striking qualities. They never ever give up. When _____________(question) by the media, they are not _____________(discourage) and practise even harder. They are improving themselves by attending several master training class. They are united. _____________(fill with) team spirit, they act as a whole, always aiming for glory. Step 6 Difference and similarity from -ingObserve the following examples.1. He went out, shutting the door behind him.=He went out, ________________________________________________________.2. Not knowing what to do, he went to his parents for help.=__________________________________________, he went to his parents for help.Similarity: _______________________________________________________________________________________________________________________________________________________.Difference : _______________________________________________________________________________________________________________________________________________________.Step Practice1. ________ in a hurry, this article was not so good. 因为写得匆忙, 这篇文章不是很好。2. ________ carefully, he found something he hadn’t known before. 他仔细读书时, 发现了一些从前不知道的东西。3. ________ why he did it, the monitor said it was his duty. 当被问及他为什么要这么做时, 班长说这是他的职责

  • 人教版高中政治必修3第六课我们的中华文化精品教案

    人教版高中政治必修3第六课我们的中华文化精品教案

    (三)、中华之瑰宝.民族之骄傲1.我国各具特色的民族文化异彩纷呈.都为中华文化的形成和发展做出了重要贡献(1)我国的雕刎建筑艺术是各族人民共同创造的,都是中华文化的瑰宝。例如:敦煌石窟、云冈石窟;克孜尔千佛洞等,是古代的汉族、鲜卑以及西域各族的艺术家和劳动人民共同创造的。(2)许多少数民族用自己的语言文字创造了优秀的民族文学。例如:藏族的《格萨尔王传》、蒙古族的《江格尔》和柯尔克孜族的《玛纳斯》被并为三大英雄史诗。◇注意:民族文化深深地体现着各民族的风俗和精神面貌,通过一定的物质展现,可以表现在建筑、民族文学、舞蹈、习俗、信仰、衣着等方方面面。◇点拨:“相关链接”中提到的《江格尔)是蒙古族卫拉特郝英雄史诗。史诗的篇幸结构、故事情节、语言风格等具有蒙古族说唱艺术的特点。从民族文学角度反映了本民族的文化生活.同时也为中华文化增添了绚丽色彩。◇课堂探究:(1)你还知道哪蝗少数民族舞蹈?它们务有什么特点?

  • 人教版高中历史必修3宋明理学教案2篇

    人教版高中历史必修3宋明理学教案2篇

    二、程朱理学:1、宋代“理学”的产生:(1)含义:所谓“理学”,就是用“理学”一词来指明当时两宋时期所呈现出来的儒学。广义的理学,泛指以讨论天道问题为中心的整个哲学思潮,包括各种不同的学派;狭义的理学,专指程颢、程颐、朱熹为代表的,以“理”为最高范畴的学说,称为“程朱理学”。理学是北宋政治、社会、经济发展的理论表现,是中国古代哲学长期发展的结果,是批判佛、道学说的产物。他们把“理”或“天理”视作哲学的最高范畴,认为理无所不在,不生不灭,不仅是世界的本原,也是社会生活的最高准则。在穷理方法上,程颢“主静”,强调“正心诚意”;程颐“主敬”,强调“格物致知”。在人性论上,二程主张“去人欲,存天理”,并深入阐释这一观点使之更加系统化。二程学说的出现,标志着宋代“理学”思想体系的正式形成。【合作探究】宋代“理学”兴起的社会条件:

  • 人教版新课标高中物理必修2功率教案2篇

    人教版新课标高中物理必修2功率教案2篇

    1.用CAI课件模拟汽车的启动过程。师生共同讨论:①如果作用在物体上的力为恒力,且物体以匀速运动,则力对物体做功的功率保持不变。此情况下,任意一段时间内的平均功率与任一瞬时的瞬时功率都是相同的。②很多动力机器通常有一个额定功率,且通常使其在额定功率状态工作(如汽车),根据P=FV可知:当路面阻力较小时,牵引力也小,速度大,即汽车可以跑得快些;当路面阻力较大,或爬坡时,需要比较大的牵引力,速度必须小。这就是爬坡时汽车换低速挡的道理。③如果动力机器在实际功率小于额定功率的条件下工作,例如汽车刚刚起动后的一段时间内,速度逐渐增大过程中,牵引力仍可增大,即F和v可以同时增大,但是这一情况应以二者乘积等于额定功率为限度,即当实际功率大于额定功率以后,这种情况不可能实现。

  • 人教版新课标高中物理必修2平抛运动教案2篇

    人教版新课标高中物理必修2平抛运动教案2篇

    (五)平抛运动规律的应用例1:一架老式飞机在高出海面45m的高处,以80m/s的速度水平飞行,为了使飞机上投下的炸弹落在停在海面上的敌船,应该在与轰炸目标的水平距离为多远的地方投弹?不计空气阻力。分析:对于这道题我们可以从以下几个方面来考虑:(1)从水平飞行的飞机上投下的炸弹,做什么运动?为什么?(2)炸弹的这种运动可分解为哪两个什么样的分运动?3)要想使炸弹投到指定的目标处,你认为炸弹落地前在水平方向通过的距离与投弹时飞机离目标的水平距离之间有什么关系?拓展:1、式飞机在高出海面45m的高处,以80m/s的速度水平飞行,尾追一艘以15m/s逃逸的敌船,为了使飞机上投下的炸弹正好击中敌船,应该在与轰炸目标的水平距离为多远的地方投弹?不计空气阻力。2、在一次摩托车跨越壕沟的表演中,摩托车从壕沟的一侧以速度v=40m/s沿水平方向向另一侧,壕沟两侧的高度及宽度如图所示,摩托车可看做质点,不计空气阻力。(1)判断摩托车能否跨越壕沟?请计算说明(2)若能跨过,求落地速度?

  • 人教版新课标高中物理必修2向心力教案2篇

    人教版新课标高中物理必修2向心力教案2篇

    3.进一步体会力是产生加速度的原因,并通过牛顿第二定律来理解匀速圆周运动、变速圆周运动及一般曲线运动的各自特点。(三)、情感、态度与价值观1.在实验中,培养学生动手、探究的习惯。2.体会实验的意义,感受成功的快乐,激发学生探究问题的热情、乐于学习的品质。教学重点1.体会牛顿第二定律在向心力上的应用。2.明确向心力的意义、作用、公式及其变形,并经行计算。教学难点1.对向心力的理解及来源的寻找。2.运用向心力、向心加速度的知识解决圆周运动问题。教学过程(一)、 引入新课:复习提问:匀速圆周运动的物体的加速度——向心加速度,它的方向和大小有何特点呢?学生回答后进一步引导:那做匀速圆周运动物体的受力有什么特点呢?是什么力使物体做圆周运动而不沿直线飞出?请同学们先阅读教材

  • 人教版高中政治必修4第四课探究世界的本质教案

    人教版高中政治必修4第四课探究世界的本质教案

    二是中国人口多、资源相对不足日益成为制约发展的突出矛盾。我国人均水资源拥有量仅为世界平均水平的1/4,600多个城市中,400多个缺水,其中110个严重缺水。我国人均耕地拥有量不到世界平均水平的40%。石油、天然气、铜和铝等重要矿产资源的人均储量分别只占世界人均水平的8.3%、4.1%、25.5%、9.7%。三是我国这20年来经济快速发展,能源浪费大、环境破坏严重等问题日益凸显,人与自然的矛盾从未像今天这样突出。无序、无度的消耗,迅速透支我们宝贵的资源。以下是来自国家环保总局的一组沉甸甸的数据。——从上世纪50到90年代,每年沙化土地扩大面积从560平方公里增加到2460平方公里,我国18个省的471个县、近4亿人口的耕地和家园正受到不同程度的荒漠化威胁。——1952年我国人均耕地2.82亩,2003年人均耕地减少到1.43亩,在各地轰轰烈烈的“圈地”热潮中仅最近7年全国耕地就减少了1亿亩,被占耕地大量闲置。

  • 人教版高中政治必修4第五课把握思维的奥妙教案

    人教版高中政治必修4第五课把握思维的奥妙教案

    2.人工智能、信息及其对意识论的深化现代科学的发展,特别是以信息论、控制论、电子计算机科学和脑科学相结合为理论基础的人工智能技术的发展,进一步证明了辩证唯物主义关于物质和意识的相互关系的原理,也给这种现代唯物主义提出了需要深入探索和解释的许多哲学问题。在这些问题之中,人工智能和信息尤为重要。人工智能是相对于人的自然智能而言的。所谓自然智能,是指人所特有的自觉的意识能力,特别是抽象思维能力。由于这种能力是人的一种天赋,所以将其称为人的自然智能。所谓人工智能,则指凭借电子计算机所实现的对人的某些智能的模拟,通过这种思维模拟,使人的某些智能得以再现和放大。自从电子计算机在20世纪中期问世以来,其作用越来越广泛,模拟功能越来越强,更新换代越来越快,对生产和社会生活的影响也越来越大。自50年代中期开始,人工智能便以计算机作为主要的支持手段,逐渐发展成为一门新兴的科学技术。

  • 人教版高中政治必修4第五课把握思维的奥妙精品教案

    人教版高中政治必修4第五课把握思维的奥妙精品教案

    【导入新课】2005年10月17日凌晨,5天前从酒泉卫星发射中心起航的“神舟”六号飞船,在平安飞行115个小时32分后重返神州,缓缓降落在内蒙古四子王旗主着陆场的草地上。我国首次真正意义上有人参与的空间飞行试验取得圆满成功。 当费俊龙和聂海胜先后自主出舱,面带胜利的微笑,现场参试人员欢呼雀跃,亿万中华儿女为之自豪,幸福写在每个人的脸上。神六飞行是一次非常完美的飞行任务,又一次让载人航天精神“从地面升到天空,从天空安全返回”。伟大的事业孕育伟大的精神。新一代航天人在攀登科技高峰的伟大征程中,以特有的崇高境界、顽强意志和杰出智慧,铸就了载人航天精神,这就是特别能吃苦、特别能战斗、特别能攻关、特别能奉献的精神。【思考讨论】“伟大的事业孕育伟大的精神”体现怎样的哲学道理?我国为什么要提倡发扬“特别能吃苦、特别能战斗、特别能攻关、特别能奉献”的载人航天精神?(人具有主观能动性)

  • 人教版高中政治必修4第九课唯物辩证法的实质和核心精品教案

    人教版高中政治必修4第九课唯物辩证法的实质和核心精品教案

    a矛盾的同一性是矛盾双方相互吸引、相互联结的属性和趋势。它有两方面的含义:一是矛盾双方相互依赖,一方的存在以另一方的存在为前提,双方共处于一个统一体中;同一事物都有对立面和统一面两个方面,一方的存在以另一方为条件,彼此谁都离不开谁(形影想随、一个巴掌拍不响、不是冤家不聚头)。【举例】P67漫画:他敢剪吗?悬挂在山崖上的两个人构成一种动态的平衡。【举例】磁铁(S极和N极);没有上就没有下、没有香就没有臭、没有福就无所谓祸;【举例】父子关系(父亲之所以是父亲,因为有儿子,儿子之所以是儿子,因为有父亲);师生关系;二是矛盾双方相互贯通,即相互渗透、相互包含,在一定条件下可以相互转化。 【相关衔接】P68生物变性现象,雌雄转化现象【举例】生产与消费具有直接统一性

  • 人教版高中政治必修4第八课唯物辩证法的发展观教案

    人教版高中政治必修4第八课唯物辩证法的发展观教案

    1973年4月的一天,一名男子站在纽约的街头,掏出一个约有两块砖头大的无线电话,并开始通话。这个人就是手机的发明者马丁,当时他是摩托罗拉公司的工程技术人员。这是当时世界上第一部移动电话。1985年,第一台现代意义上的可以商用的移动电话诞生。它是将电源和天线放置在一个盒子里,重量达3公斤。与现代形状接近的手机诞生于1987年,其重量大约750克,与今天仅重60克的手机相比,像一块大砖头。此后,手机的“瘦身”越来越迅速。1991年,手机重量为250克左右。1996年秋,r出现了体积为100立方厘米、重量100克的手机。此后,又进一步小型化,轻型化,到1999年就轻到了60克以下。手机的体积越来越小,但功能却越来越多。以前的手机是用来通话的,现在的手机是用来享受的。今天,手机可以是相机、游戏机、音乐播放器、信用卡、电影院……手机带来的不仅仅是通信方式的改变,更是生活方式的变革。

  • 人教版高中政治必修3第三课文化的多样性与文化传播精品教案

    人教版高中政治必修3第三课文化的多样性与文化传播精品教案

    ◇探究提示:我们可以通过人际交往,阅读报纸、杂志、书籍等,欣赏电视、上网查询、发送手机短信、阅读电子读物等方式来搜集资料。其特点为:人际传播是社会生活中最直观、最常见、最丰富的传播现象,具有传播渠道多、方法灵活、意义丰富、反馈及时的特点。报纸、杂志、书籍等,可以通过扫描、编排处理后,显示在互联网上,供广大读者使用。电视提供了动态画面和缤纷的色彩,使人们对信息的理解变得更生动、形象和真实。互联网具有传播同网、全球同时、受众主动、双向互动的特点。手机短信用精练的语言传达丰富多彩的内容,不仅具有娱乐性,还具有情感性、艺术性耙哲理性,让人回味无穷。电子读物实现了文字、图像、声音的完关结合,使人在看图阅文的同时可以听音乐、写文章、做笔记、复制文件等等。

  • 人教版高中政治必修4第七课唯物辩证法的联系观教案

    人教版高中政治必修4第七课唯物辩证法的联系观教案

    2.能力目标(1)通过本课的学习,要求着重培养学生全面地、联系地看问题和分析问题的能力;培养学生综合运用知识的能力,以及运用所学知识分析、处理和解决实际问题的能力。(2)使学生初步具有从错综复杂的联系中认识和发现事物本质的、固有的、内在的联系的能力,初步学会用全面的、联系的观点看问题的能力。(3)使学生初步具有坚持和把握整体与部分辩证关系的能力,初步具有运用系统优化的方法安排自己学习和生活的能力。在处理问题时,既要看到整体与部分之间的联系又要看到它们的区别,掌握系统优化的方法,学会运用综合性的思维方式认识事物和处理生活、学习和工作中的问题。3.情感、态度和价值观目标(1)树立唯物辩证法的联系观,自觉抵制形而上学的静止观。坚持用联系的观点看问题,自觉维护人类生存的环境,确信一切以时间、地点和条件为转移,是我们正确认识和把握事物、在认识世界和改造世界的活动中不断取得成功的关键。

  • 人教版高中政治必修4第八课唯物辩证法的发展观精品教案

    人教版高中政治必修4第八课唯物辩证法的发展观精品教案

    2、理解目标(1)发展的普遍性;(2)事物发展的道路和方向;事物发展的形式;3、运用目标(1)根据所学知识,结合相关原理,分析说明自然界、人类社会是无限发展的。了解唯物辩证法是关于世界普遍联系的科学,又是关于世界永恒发展的科学。(2)根据有关原理,理解事物发展的前途是光明的,道路是曲折的,说明新事物必然战胜旧事物是宇宙间不可抗拒的规律。(3)结合古人有关的名言警句,组织学生讨论生活和学习中的具体问题,分析量变和质变的辨证统一关系对于生活和实践的意义。二、能力目标1、通过学习,培养学生正确认识事物发展的方向、发展的道路和发展的形式,用发展的眼光看问题、分析问题的能力。2、使学生初步具有运用科学发展观观察、分析和处理自然和社会现象的能力。3、使学生初步形成正确对待生活中的失败与成功、困难挫折与理想目标之间关系的能力。

上一页123...131415161718192021222324下一页
提供各类高质量Word文档下载,PPT模板下载,PPT背景图片下载,免费ppt模板下载,ppt特效动画,PPT模板免费下载,专注素材下载!

PPT全称是PowerPoint,LFPPT为你提供免费PPT模板下载资源。让你10秒轻松搞定幻灯片制作,打造⾼颜值的丰富演示文稿素材模版合集。