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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
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
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
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 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
新人教版高中英语必修2Unit 5 Music-Reading and Thinking教案二
1. Get basic information about Eric; read deeply to understand the history and development of the virtual choir.2. Understand what the function of the virtual choir is and how to make a virtual choir.3. Understand the meaning of some languages in the context of the text through question guidance, such as “Many people do not have close friends or contacts who have the same interest in music.” and so on.Step 1 Leading-in1. Answer the following questions.Q1：Do you know the Apps like Tik Tok and Quick Hand?Q2: Do you want to make a Tik Tok video or a Quick Hand video?2. Play a Tik Tok video Step 2: Understanding the title Q1：What does the title mean ?Q2: Is the article a narration or exposition? Why? Q3: Can you change the title ? If you can, what is the title?Step 3: Scanning the whole text and getting the basic information1. Answer the following questions.Q1：Who came up with the idea for a virtual choir?Q2: Where did Eric studied the musical composition?Q3: What is his song?2. Find the main idea of each paragraph3. Deal with some new words.Step 4: Reading carefully to get detailed informationPara 1 How to make a virtual choir1. PreparationA. tools: a virtual camera; an Internet connectionB. hero/heroin: friends or some individuals who have the same interests2. Process
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3Unit 1 Festivals and Celebrations教学设计二
1. Ss look at the picture and scan the passage to understand the main idea while teacher is giving the following questions to inspire Ss to think.*Where are those people?*What are they doing?*Why are they so excited?2. Ss complete the passage with the appropriate -ing form. Then discuss and check the answers with class.Answers: boring, interesting, taking, exciting, amazing3. The teacher raises questions for the students to discuss and encourages them to express their opinions.*Do you like La Tomatina? Why or why not?4. Each group representative reports the discussion result, the teacher gives feedback and the evaluation.Step 6 PracticeActivity 41. Ss complete the Ex 2 in Using structures.2. Check the answers after finishing the exercises.①The dragon boat races are the most exciting part of the Dragon Boat Festival.② The children were excited to go Easter egg hunting.③What an amazing performance! This is the best music festival I have ever been to.④We were amazed by her funny-looking hat.⑤His inspiring speech at the conference won the admiration/ favour of the audience.⑥This is a challenging game to test your memory and observation capabilities. 3. T asks Ss to finish Ex 3 and 4 in Using structures by themselves, then check the answers with class.Step 6 Homework1. Understand and master the functions and usage of the -ing form;2. Finish the other exercises in Using structures.1、通过本节内容学习，学生是否理解和掌握动词-ing形式作定语和表语的功能和意义；2、通过本节内容学习，学生能否在理解文段内容的基础上，根据上下文语境和表达逻辑，能正确运用动词-ing形式描述节日庆典。3、通过本节内容学习，学生是否归纳和积累用于表达情绪的相关词汇。
新人教版高中英语必修3Unit 2 Morals and Virtues教学设计二
Activity 41. Students complete the task of activity 4, then teachers and students check the answers. 2. The teacher organized the students to work together and asked them to use the tables and mind maps sorted out before to retold the important choices in Lin Qiaozhi's life and their resultsStep 5 Language points1. The teacher asks the students to read the text carefully, find out the core words and long and difficult sentences in the text and draw lines, understand the use of vocabulary, and analyze the structure of long and difficult sentences. 2. The teacher explains and summarizes the usage of core vocabulary and asks the students to take notes. 3. The teacher analyzes and explains the long and difficult sentences that the students don't understand, so that the students can understand them better. Step 6 Homework1. Read the text again, in-depth understanding of the text; 2. Master the use of core vocabulary and understand the long and difficult sentences. 3. Complete relevant exercises in the guide plan. 1、通过本节内容学习，学生是否理解和掌握阅读文本中的新词汇的意义与用法；2、通过本节内容学习，学生能否结合文本特点总结林巧稚的人生原则和人格品质特征；3、通过本节内容学习，学生能否针对人生抉择发表自己的看法；能否全面地、客观地、理性地看待问题，进而对道德和人性有更加深入的思考和理解。
新人教版高中英语必修3Unit 3 Diverse Cultures教学设计二
(2)Consolidate key vocabulary.Ask the students to complete the exercises of activity 6 by themselves. Then ask them to check the answers with their partners.(The first language:Damage of the 1906 San Francisco earthquake and fire.A second language: Yunnan - one of the most diverse provinces in China).Step 5 Language points1. The teacher asks the students to read the text carefully, find out the more words and long and difficult sentences in the text and draw lines, understand the use of vocabulary, and analyze the structure of long and difficult sentences.2. The teacher explains and summarizes the usage of core vocabulary and asks the students to take notes.3. The teacher analyzes and explains the long and difficult sentences that the students don't understand, so that the students can understand them better.Step 6 Homework1. Read the text again, in-depth understanding of the text;2. Master the use of core vocabulary and understand the long and difficult sentences.3. Complete relevant exercises in the guide plan.1、通过本节内容学习，学生是否理解和掌握阅读文本中的新词汇的意义与用法；2、通过本节内容学习，学生能否结合文本特点了解文章的结构和作者的写作逻辑；3、通过本节内容学习，学生能否了解旧金山的城市风貌、文化特色，以及加利福尼亚州的历史，体会多元文化对美国的影响。
人教版高中地理必修2如何看待农民工现象精品教案
尽管如此，农民工作为一个新的社会阶层，其独特的经济需求和政治诉求应该得到充分的尊重。虽然农民工的“根”还在农村，但是他们已经脱胎换骨，日益成长为一个迫切需要社会认可的新兴阶层。3.农民工处于何种生存境况？作为“廉价劳动力”，工资水平低，拖欠时有发生。作为“超时劳动力”，工作时间极长，超负荷从事繁重工作。作为“高危劳动力”，社会保障缺失，各种安全事故频繁。4.农民工问题有多么重要？农民工问题关系到农业增效、农民增收和农村繁荣。农民工问题关系到工业化、城镇化和“以工补农、以城促乡”。农民工问题关系到社会主义和谐社会建设。5.解决农民工问题应该做些什么？构建城乡一体化就业体系。健全农民工权益保障制度。强化农民工输出地和输入地培训。稳妥解决农民工户籍问题。改进对农民工的管理和服务。
人教版高中生物必修3第六章第一节《人口增长对生态环境的影响》说课稿
3、讨论问题二：我国、我市人口增长对环境有那些影响？教师：让第三、第四组学生分别介绍、展示课前调查到的资料，说明人口增长对我国环境的影响、对三亚市环境的影响。学生：第三组学生派代表介绍人口增长过快对我国生态环境的影响。第四小组由学生自己主持“我市人口增长过快对三亚市生态环境的影响”讨论会，汇报课前调查到的资料和讨论，其它小组参与发言。教师：投影：课本图6－2组织学生讨论、补充和完善。学生：观察老师投影图片并进行讨论，对图片问题进行补充和完善。教学意图：通过让学生汇报、观察、主持，能让学生亲身体验，更深刻地理解人口增长对生态环境的影响，培养和提高学生的表达能力、观察能力、主持会议的能力。4、讨论问题三：怎样协调人与环境的关系?教师：组织第五组学生进行汇报课前调查到的资料，交流、讨论、发表意见和见解。学生：展示课件、图片，汇报调查到的情况，提出合理建议。
《装在套子里的人》说课稿 2021-2022学年统编版高中语文必修下册
8、板书装在套子里的人别里科夫的形象——有形的套子套己——无形的套子套人第二课时合作探究：目标挖掘主题及现实意义。问题设置，衔接上节课内容，层层深入。1、结合上节课别里科夫的形象分析：他的思想被什么套住，其悲剧原因在哪？（根据人物形象的分析与社会背景的了解，直击主题。）沙皇腐朽的专制统治套住了他的思想，沙皇的清规戒律使他不敢越雷池一步，所以他是受害者，但他的身份性格以及特定的社会环境，又让他成为沙皇统治的捍卫者。2、他恋爱的情节以及科瓦连科这两个人物的塑造的意义？（从人物以及主题入手，推翻沙皇的腐朽反动的统治，必须是每一个人都敢于打破套子，唤醒革新，更新观念，拒绝腐朽。）别里科夫渴望打破束缚，也想革新，而科瓦连科两个人物体现朝气活泼，以及勇于打破常规束缚的勇气，为革新升起了一片曙光。3、塑造别里科夫的手法，除了一般刻画人物方法外，还有什么方法？
人教版高中历史必修1祖国统一大业教案2篇
教材分析改革开放后我国的综合国力不断增强，人民对祖国统一的愿望越来越迫切。本节课以“一国两制”构想的提出，香港、澳门的回归和海峡两岸关系的发展为中心，说明实现祖国统一，完成中华民族复兴是历史发展的必然。第一目“‘一国两制’构想的提出”主要讲述了“一国两制”的含义及历史意义。第二目“香港、澳门的回归”着重讲述了香港回归、澳门回归的经过及历史意义，这是“一国两制”成功的实践。第三目“海峡两岸关系的发展”讲述了大陆注重发展与台湾的关系，促进海峡两岸的经济文化交流与合作，打破了几十年来海峡两岸的隔绝状态，促进了祖国统一的进程。此外，教材还通过“资料回放”“历史纵横”“学思之窗”等栏目，为学生学习提供了一些详细的史料。在教学中要分析图表资料，引导学生理解完成祖国统一大业，实现中华民族的复兴，是任何人也阻挡不了的历史潮流。
新人教版高中英语必修2Unit 4 History and Traditions-Listening＆Speaking＆Talking教案一
This unit is about history and traditions. From the opening page, we can know that this unit will introduce the history and traditions around the world. As Marcus Garvey says “A people without the knowledge of their past history, origin and culture is like a tree without roots”, it is important for students to realize the importance and value of knowing the history and traditions and their further meanings. And this part ( listening and speaking ) is divided into two parts: Part A---share views on historic sites, Part B ---talk about a visit to a historic tourist destination. By talking with a foreigner, the speakers introduce the historic attractions and their cultures. Part A is that William, a British student, who was going to visit the Confucius Temple and a Chinese student, Xiao Kong, who was going to the Confucius Temple to meet with the members of the research group, went together and exchanged their views on the Confucius Temple, Confucius, Confucius' descendants and Confucius' educational thoughts. Part B is a conversation between Xiao Yan, a youth hostel receptionist and Paul, a backpacker about the feelings and experience after visiting the Chinese famous tourist attraction Pingyao.1. Guide students to understand the content of listening texts in terms of the whole and key details; 2. Cultivate students' ability to guess the meaning of words in listening; discuss with their peers how to talk about historic spots and great person.3. Instruct students to use functional sentences of showing one’s excitement, surprise and disappointment.1. Guide students to understand the content of listening texts in terms of the whole and key details; 2. Cultivate students' ability to discuss with their peers the related topics.3. Enable students to use the functional items of showing one’s excitement, surprise and disappointment.
新人教版高中英语必修2Unit 4 History and Traditions-Reading and Thinking教案一
Features of languages1．Finally, in the 20th century, the southern part of Ireland broke away from the UK, which resulted in the full name we have today: the United Kingdom of Great Britain and Northern Ireland．该句是一个复合句。该句主句为：the southern part of Ireland broke away from the UK；which resulted in the full name we have today为which引导的定语从句代指前面整句话的内容，we have today为定语从句修饰先行词name。译文：最后，在20世纪，爱尔兰南部脱离英国，这导致了我们今天有的英国的全名：大不列颠及北爱尔兰联合王国。2．Almost everywhere you go in the UK, you will be surrounded by evidence of four different groups of people who took over at different times throughout history．该句是一个复合句。该句主句为：you will be surrounded by evidence of four different groups of people；其中Almost everywhere you go in the UK为让步状语从句； who took over at different times throughout history为定语从句修饰先行词people。译文：几乎无论你走到英国的任何地方，你都会发现历史上有四种不同的人在不同的时期统治过英国。3．The capital city London is a great place to start, as it is an ancient port city that has a history dating all the way back to Roman times．该句是一个复合句。该句主句为：The capital city London is a great place to start; as it is an ancient port city that has a history dating all the way back to Roman times．为原因状语从句；dating all the way back to Roman times为现在分词短语作定语修饰history。
新人教版高中英语必修2Unit 4 History and Traditions-Discovering Useful Structure教案一
Step 5 Practice一、完成下列句子。1. Judy and I _______________（把车停下来(park)）in an underground car Park near Trafalgar Square, where we could ______________________(让我们的车充电（charge)).2. When we finally reached the service desk to ask for audio guides, we heard it ___________ that there were no audio guides____________(留下，剩下）.3. We__________________________（发现自己对...很惊讶）the large number of visitors and the amount of noise at the entrance of the National Gallery.4. Judy ____________________(眼神专注于） Van Gogh’s Sunflowers. It was hard to approach the painting as there were so many people around.5. She ____________________(把这幅画的复制品装箱（box)） to ensure that it was delivered safely.答案：1.had our car parked get our car battery charged 2. announced left 3. found ourselves very surprised 4. had her eyes fixed on 5. had a copy of the painting boxed二、用过去分词对下列句子进行改写。1. Loch Ness was surrounded by beautiful natural landscape, which made it look amazing.2. Carl and his friend stayed with a generous family who offered them bread with butter and honey that was homemade.3. The family’s ancestors once attended to soldiers who were wounded in the First World War.4. The young people were attracted by the legend of Loch Ness. They watched over the lake with their cameras and binoculars, which were positioned on the hill.答案：1. Loch Ness surrounded by beautiful natural landscape looks amazing.2. Carl and his friends stayed with a generous family who offered them homemade bread with butter and honey.3. The family’s ancestors once attended to wounded soldiers in the First World War.4. The young people attracted by the legend of Loch Ness watched over the lake with their cameras and binoculars positioned on the hill.
人教版高中历史必修2二战后苏联的经济改革教案
⑤强调对外关系的灵活性。戈尔巴乔夫指出在对外政策中要采取多种办法选择不同的策略路线达到既定目标。在外交谈判中不要为自己制造死胡同，也不要给对方制造死胡同，要善于迎合伙伴，寻求接触点。在这种思想指导下，苏共采取的对外战略是以军控为中心的缓和战略，具体政策是继续与美国就裁军、消减核武器、限制地区冲突等问题进行谈判，缓解苏美关系；对西欧争取建立“全欧大厦”；对东欧实行纠偏、不干涉政策；对中国改善关系，实现关系正常化；调整与第三世界国家关系，解决阿富汗、柬埔寨等问题。 3、影响：①经济改革措施仓促上马，缺少宏观决策和相应的配套措施；加上戈尔巴乔夫没有放弃苏联的传统做法，继续优先发展重工业，致使改革未达到预期的效果，苏联经济持续下滑②经济体制改革受挫后，把改革的重点转向政治领域，最终导致国内局势的失控和苏联的解体。
人教版高中地理必修1第五章第二节自然地理环境的差异性教案
【补充说明】我们这节课简要地分析了陆地环境的三种地域分异规律。实际上，世界上的任何事物有其一般性，也有它的特 殊性。在地带性分异规律的基础上，陆地环境因为受到海陆分布、地形 起伏等因素的影响，也会出现一些不规律的现象，这种现象称为非地带性。例如，我们在初中地理中学过绿洲。还记得什么叫绿洲吗？再比如，在南美洲的西海岸（太平洋沿岸），有一条狭长的（热带）荒漠带，而缺少热带草原带，热带雨林带主要是分布在赤道以北地区。这主要是受大的地形起伏的影响。因为南美洲西部是一列高大的安第斯山脉，受其影响，两边的气候状况不同，所以就出现了分布规律不同的自然带，这也是一种非地带性现象。【总结】有规律分布的自然带构成了全球和谐的自然环境整体。自然带之间错综复杂的、微妙的要素关系，有许多是人类还没有认识到的。因此，人类不能随意去破坏任何哪怕是极微小的环节，也许它 带来的影响会是全球性的。保护全球环境，人人有责。
人教版高中数学选择性必修二导数的四则运算法则教学设计
求函数的导数的策略(1)先区分函数的运算特点，即函数的和、差、积、商，再根据导数的运算法则求导数；(2)对于三个以上函数的积、商的导数，依次转化为“两个”函数的积、商的导数计算．跟踪训练1 求下列函数的导数：(1)y＝x2＋log3x； (2)y＝x3·ex； (3)y＝cos xx.[解] (1)y′＝(x2＋log3x)′＝(x2)′＋(log3x)′＝2x＋1xln 3.(2)y′＝(x3·ex)′＝(x3)′·ex＋x3·(ex)′＝3x2·ex＋x3·ex＝ex(x3＋3x2)．(3)y′＝cos xx′＝?cos x?′·x－cos x·?x?′x2＝－x·sin x－cos xx2＝－xsin x＋cos xx2.跟踪训练2 求下列函数的导数（1）y＝tan x； （2）y＝2sin x2cos x2解析：（1）y＝tan x＝sin xcos x，故y′＝?sin x?′cos x－?cos x?′sin x?cos x?2＝cos2x＋sin2xcos2x＝1cos2x.（2）y＝2sin x2cos x2＝sin x，故y′＝cos x.例5 日常生活中的饮用水通常是经过净化的，随着水的纯净度的提高，所需进化费用不断增加，已知将1t水进化到纯净度为x%所需费用（单位：元），为c(x)=5284/(100-x) (80<x<100)求进化到下列纯净度时，所需进化费用的瞬时变化率：（1） 90% ；（2） 98%解：净化费用的瞬时变化率就是净化费用函数的导数；c^' (x)=〖(5284/(100-x))〗^'=(5284^’×(100-x)-"5284 " 〖(100-x)〗^’)/〖(100-x)〗^2 =(0×(100-x)-"5284 " ×(-1))/〖(100-x)〗^2 ="5284 " /〖(100-x)〗^2