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人教版高中语文必修2《短歌行》说课稿2篇
一、说教材《短歌行》是普通高中课程标准实验教科书必修（二）第二单元的一篇略读课文，本单元安排的是先秦到南北朝时期的诗歌。《短歌行》是著名政治家、军事家、文学家曹操的作品。诗中抓住“忧”字来写诗人为什么“忧”，如何解“忧”，从而表达希望能够招揽人才、完成统一天下的雄心壮志。所以本单元安排《短歌行》一诗，对学生全面了解曹操，感受曹操在短暂的人生中竭力创造伟业的气概。二、说学生我这一课的教学对象是高一学生。他们进入高中学习的时间只有三个多月，现在已经完成了必修（一）的学习。学习了现代诗歌单元，有了一定的诗歌学习基础，初步掌握了读诗的基本方法，但是还未能形成成熟的稳定的学习方式。同时，本单元学习是高中第一次接触古代诗歌，诗歌语言上的障碍和时间上的跨度对他们来说都是学习上的困难。因此教师要引导学生自主学习，合作学习，为他们设置新的学习情境，提供合作探究的机会。
人教版高中语文必修2《游褒禅山记》说课稿3篇
学法指导：高一学生对文言文阅读已具备了一些基础知识和积累，但对如何学习文言文，还是一个新课题，因此教师应引导学生掌握学习方法，运用已有的知识框架同化新信息，建立新的智能，逐步走向独立学习的境界。一、引导学生利用课文注释，使用工具书自己翻译，必要时教师进行点拨、解难，培养自学能力。二、告诉学生翻译文言文要遵循的原则。三、调动学生思考、讨论、交流的积极性，教师适时点拨，培养学生发现问题、解决问题的能力。四、提示学生反复诵读课文，体会文章所阐述的道理。五、鼓励学生及时归纳学习文言文的方法，注意积累文言文知识。教学程序：教学本课可安排2课时。第一课时：1、导入新课：首先给学生介绍毛泽东的七绝诗《为李进同志题所摄庐山仙人洞照》：“暮色苍茫看劲松，乱云飞渡仍从容。天生一个仙人洞，无限风光在险峰。”学生通过诵读领会了“无限风光在险峰”一句的含义。随后因势利导，引出课题，指出今天我们要学习的王安石的《游褒禅山记》，就含有类似的深邃哲理。
人教版高中语文必修3《琵琶行 并序》说课稿2篇
说教材A．教材简析《琵琶行（并序）》是人教版《普通高中课程标准实验教科书语文》必修3第二单元的一篇讲读课文。本单元学习的是唐代诗歌，共七首诗。《琵琶行（并序）》是唐代著名现实主义诗人白居易写的一首歌行体长篇叙事诗，是我国古代叙事诗和音乐诗中的“千古绝喝”。诗歌主题鲜明、人物形象生动，抒情真切细腻，具有深刻的思想内容和卓越的艺术技巧。B．教学目标《全日制普通高中高级中学语文教学大纲》明确要求我们：在阅读教学过程中要引导学生“感受文学形象，品味文学作品的语言和艺术技巧，初步鉴赏文学作品”。而本单元的教学要求是培养学生诗歌鉴赏的能力。根据教学大纲和单元教学要求，结合本课特点，我制定本课的教学目标是：1．知识目标：了解文学常识；积累重点文言实词；品味主旨句“同是天涯沦落人，相逢何必曾相识”的内涵；感知作者把音乐描写与听者、演奏者的感情融为一体的写作特点。
人教版高中语文必修3《蜀道难》说课稿2篇
（1）“问君西游何时还……使人听此凋朱颜。”诗题下未注明送何人入蜀，所以这里的“问君”无妨假定实有其人，可以读得亲切一些。将行而问“何时还”，已有不可行之意，重音要落在“不可攀”三字上，当用劝说的语气读。以下四句借鸟声渲染旅途中悲凉凄清的氛围，读时要放低声调，有干里孤身之感，至“愁空山”徐徐而上。然后用感喟的语调读主旨句，至“凋朱颜”略作一顿，以示意犹未尽。（2）“连峰去天不盈尺……胡为乎来哉！”仍是说不可行，但内容加深了一层，因为说的是蜀道的险恶。前四句不是纯客观的描写，读时须设想这是旅游者攀援于“连峰”“绝壁”之上置身于“飞湍瀑流”之间，要使听者感到惊心动魄。读后可作稍长停顿，再用“其险也如此”缓缓收住。末句是诗人借用蜀人的口气，对历险而来的游者深表叹息——“胡为乎来哉”不是询问，当用降调读，暗含“何苦而来”之意。
人教版高中语文必修3《祝福》说课稿3篇
各位评委老师，大家好。我说课的题目是《祝福》。一、说教材（一）教材所处的位置和地位高中语文新课程教材必修五本书，共有2个单元中外小说单元。一个必修3的第一单元，一个是必修5的第一单元，共六篇文章。（《林黛玉进贾府》《祝福》《老人与海》《林教头风雪山神庙》《装在套子里的人》《边城》）《祝福》是属于前者。小说是拥有众多读者的一种文体，它可以多方面刻画人物性格，描摹人物心理，完整地表现人物之间的冲突，还可以具体生动地再现人物生活的环境，因此在反映复杂的社会生活方面具有独特优势。所以学习小说这种文学样式，也是有助于学生学会鉴赏小说的基本方法，为将来的小说阅读打下基础。鲁迅的《祝福》是中国现代小说的精品，当中的人物祥林嫂也是鲁迅小说中与阿Q、孔乙己三个最为出名的人物之一。研读好这篇文章，对将来小说的阅读，小说中人物的理解，甚至小说的写作都有深广意义。
人教版高中历史必修2罗斯福新政说课稿2篇
1、教材的地位作用本课是新人教版普通高中历史必修Ⅱ第六单元第18课的内容，阐述罗斯福新政的背景、措施、影响。从单元知识安排看，本课与第17课《空前严重的资本主义世界经济危机》、19课《战后资本主义的新变化》共同诠释第六单元课题——《资本主义世界经济政策的调整》。说明了“资本主义经济理论和政策随着资本主义发展而不断调整的特点”,凸显了“市场调节”和“国家干预”在经济发展中的重要性。从知识体系看，它是学生学习了第一次工业革命后自由资本主义、第二次工业革命后的垄断资本主义等之后出现的，既是对上述知识的巩固与综合运用，又为学生学习必修二的相关内容打下基础，有承上启下的作用。本课三个子目从逻辑上看又是递进关系。第一个子目“临危受命”承上启下，说明了罗斯福上台的历史背景具有临危受命的特点，第二个子目“实施新政”讲述了罗斯福新政的主要内容，第三个子目“摆托危机困境”主要讲述了罗斯福新政的影响。
人教版高中历史必修2开辟新航路说课稿3篇
一、说教材《开辟新航路》是高中《历史·必修二》第5课的内容。从三个方面向学生介绍了欧洲人开辟新航路的历史：即新航路开辟的原因和条件、新航路开辟经过以及影响。前4课内容介绍了古代中国经济的基本结构与特点，从第5课开始学习资本主义世界市场的形成和发展。本课内容相当重要，上承古代中国，下启近代世界。新航路的开辟，打破了世界相对隔绝的状态，世界真正开始融合为一个整体。从此，以西欧为中心的世界市场的雏形开始出现。随后的殖民扩张，世界市场拓展；第一次工业革命，世界市场基本形成；第二次工业革命，世界市场发展。二、说目标1、课程标准概述迪亚士、哥伦布开辟新航路的史实，认识地理大发现对世界市场形成的意义。2、三维目标①知识与能力：掌握新航路开辟的原因、经过、影响。②过程与方法：引导学生分析原因及影响，培养学生分析和归纳问题的能力。③情感态度与价值观：A、通过对新航路开辟过程的学习，使学生感受和学习探险家们勇于进取的开拓精神。B、通过学习新航路开辟的影响，使学生认识新航路开辟促进了人类社会的整体发展。
人教版高中生物必修2基因在染色体上说课稿
三、孟德尔遗传规律的现代解释①分离定律：在杂合体的细胞中，位于一对同源染色体上的等位基因，具有一定的独立性；在减数分裂形成配子的过程中，等位基因随同源染色体的分开而分离，独立地随配子遗传给后代。②自由组合定律：位于非同源染色体上的非等位基因的分离或组合是互不干扰的；在减数分裂过程中，同源染色体的等位基因彼此分离的同时，非同源染色体上的非等位基因自由组合。总结：再次强调孟德尔遗传定律的现代解释课堂练习：书本31页6、教学反思：本节课设置了一系列问题情境，层层设问，在学生答问、质疑、讨论过程中让学生建构新概念和新的知识体系，并通过教师及时掌握反馈信息，适时点拨、调节，让学生在推理判断中培养良好的思维习惯和对知识的迁移能力，而且通过留出一定的时间让学生提问，体现了以学生为主体的思想。
人教版高中生物必修2染色体变异说课稿
四、说教学程序（一）.温故知新、导入新课复习提问:基因突变导致生物变异的原因是什么?回答:基因突变是基因结构发生改变，从而使遗传信息改变，使蛋白质结构改变、生物性状改变，即生物发生了变异。那么，基因是什么?它和染色体又有何关系?回答:基因是有遗传效应的DNA片断，染色体是DNA的载体，基因在染色体上呈线形排列。引出新知:对于一个生物体来说，正常情况下，其染色体的结构和数量都是稳定的。但在自然条件或人为因素的影响下，染色体的结构和数量均会发生改变，从而导致生物性状的改变，这就属于染色体变异。（二）.把握重点、突破难点重点的把握：1、染色体结构的变异播放影片:猫叫综合征幼儿。让学生观察: 患儿哭声轻、音调高，很像猫叫。教师补充: 患儿的征状---两眼较低、耳位低下，存在着严重的智力障碍。阐述病因---染色体片段缺失
人教版高中政治必修3感受文化影响说课稿
（2）世界观，人生观，价值观是人们文化素养的核心和标志。一旦形成就会对人产生深远持久的影响。（但随着生活阅历的变化，人们文化素养的提高，人们的“三观”会发生变化。）总之“潜移默化”指每时每刻，不知不觉；是从文化对人影响的过程来看的。“深远持久”指经年累月，难以抹去；是从文化对人影响的结果上说的。3.课堂总结：首先启动学生思维，教会学生把握知识主线，建构知识体系，先由学生进行总结，然后教师进行必要的补充4、布置作业：布置作业。运用文化对人的影响的知识分析“近朱者赤，近墨者黑”，并且应该如何处理朋友之间的关系。设计这个作业的意图是既让学生灵活运用所学知识，同时又让学生回归生活，如何处理朋友之间的关系。5、板书设计遵循板书设计的实用性、直观性的原则，根据本课的教材特点，我采用结构式板书，这样设计比较直观、系统，以便于学生能够系统把握和理解知识。
人教版高中政治必修3聚焦文化竞争力说课稿
（1）文化与经济、政治在经济基础上相互影响。①经济、政治和文化是社会生活的三个基本领域。其中，经济是基础，政治是经济的集中表现，文化是经济和政治的反映。一定的文化由一定的经济、政治所决定，又反作用于一定的政治、经济，给予政治、经济以重大影响。②经济发展是文化发展的基础。但这并不意味着文化的发展始终与经济的发展亦步亦趋。如同不能简单地把精神文明看作是物质文明的派生物和附属品一样，也不能简单地认为文化是经济、政治的派生物和附属品。文化有其自身的传承性和相对的独立性。那种认为只要物质条件好了，精神文化自然而然地就会好起来，物质条件差一点，精神文化就不可能搞好的观点，不符合历史发展的事实，是不正确的。③掀开历史的画卷，文化既有古今和地域之别，又有先进与落后、腐朽之分。不同的文化，对经济、政治的影响不同，对社会发展的作用也不同。不同民族的文化，影响不同民族和国家各具特色的发展道路。
人教版高中英语必修2Cultural Relics说课稿2篇
Ⅲ. Analysis of the teaching material:The topic of this unit is cultural relics. Students are quite interested in topics about different cultures around the world. This is the second period of the whole unit. As a reading class, the passage mainly talks about the history of the amber room (how it was made, sent as a gift, lost and rebuilt).According to the new national curriculum, when teaching reading, much emphasis should be put on training the students’ reading skills.Ⅳ. Teaching objectives1. Language objectives:1) Students are required to master the key words and phrases occurred in the passage (e.g. amazing, decorate, belong, in return, less than etc.)2) Students are required to learn the attributive clause and acquire the sentence pattern.2. 1) Students are required to describe a certain thing by using the new sentence patterns.2) Students are required to master two kinds of reading skills—skimming and scanning, and learn to use them in their daily reading.3. 1) Students are required to know the history of the amber room.2) Students are required to appreciate cultural relics and understand the importance of protecting them.Ⅴ. Teaching important and difficult points1) the new words, phrases, and sentence pattern in the course of reading.2) Teaching difficult point: Help the students master two kinds of reading skills—skimmingand scanning and learn to apply them in daily use.Ⅵ. Teaching methods:Task-based method & Top-down model Ⅶ. Teaching aids: PPT, pictures, blackboard Ⅷ. Teaching procedure:
人教版高中英语必修2Wildlife Protection说课稿3篇
When it comes to the students’ studying methods, I'd like to introduce my Ss first. The Ss have a good command of basic language points. They’re interested in learning English, and they take an active part in English class, so they will have fun in autonomous, cooperative and inquiry learning. I will just serve as a guide, showing them the way to explore how to make more progress in their English learning.Now it’s time for the most important stage of this lesson. My teaching procedures are arranged as follows:Step1.Leading-in (3 minute)Play a video of a wide variety of wildlife to introduce my topic. Step2. Speaking (12 minutes)We will use our textbook Page25. Let the Ss fast read the short paragraph to warm up. Ask them to talk about the report on some endangered wildlife in China with the dialogue patterns on the screen. Lastly, I will invite some groups to demonstrate their dialogues about saving wildlife in China.Step3.English play (3 minutes)Watch another video in praise of their excellent performance just now. It’s about Jack Chen’s（成龙）and Yang Ziqiong’s wildlife protection.Step4. Listening (twice 13 minutes)This time, I’ll ask the Ss to fill in the blanks of the monologue of the 2 movie stars above. Step5.Discussion (3 minutes)Which would you like to choose to wear, clothes made of cotton, artificial leather or animal skins? Why ?Step6. Summary (3 minutes)1. If there were no wildlife, there wouldn’t exist human beings. If the buying stops, the killing can, too.2. Animals are our friends. To love animals is to love ourselves. Stop hunting, killing and destroying wildlife.3. Let’s live in harmony with all the living things in the world. Step7. Music appreciation (3 minutes)Let the Ss appreciate the song Earth Song by Michael Jackson. Last but not the least, I will show you my blackboard design.
人教版高中英语必修4A taste of English Humor说课稿3篇
Then I would ask them to think of a funny English or Chinese and tell it to partners. While telling stories, they can use expressions and some acting to help make the story funny. 5 minutes would be given to do this.Those stories they told there will be the material for their writing. Soletting them tell it at first is helpful. And they can make a difference between telling a funny story and writing it down. Generally speaking, it is difficult forstudents to write well because they don’t know what to write and how to write. Asking them to tell their own stories at first can help them come up with what to write.After their telling, I would invite someone to share his/her story with all of us and I would write it down on the blackboard.This example story would be used as a sample to illustrate the format of funny story. Different from a story from teacher or textbook, a story from students can obviously become a interesting material to draw students’ attention.Then I would ask the whole class to put this story into several parts. It might be a little bit difficult for them. So I would ask them to find out whether all the sentences are necessary. After delete some sentences, there are 6 sentences left behind. Then they can easily put them into three parts. After interaction with students, I would teach them the right terms for each part and conclude the format of funny story.This step is the key and difficult point in my lesson. So I mainly usetask-based teaching method in this part and the task for students was divided into several stages. With the separated difficult level, students can find there are usually three parts in writing. They can also learn to write without the unnecessary parts in the process of analyzing. And then I wouldn’t rush to tell them the right terms to them directly. Instead, I would ask them to name them by their own. A confused mind is better for acquiring knowledge.While-writing:Then I would give students 7 minutes to write down this story, without other requirements.With all the preparations in pre-writing, students’ difficulties were cleared. So it would be much easier for them to write down the story within 7 minutes. There are no other requirements because students’ first writing is actually a drafting. It would be revise and edit several times later. Writing, as a skill
人教版高中英语必修3Canada-the true north说课稿4篇
Good afternoon, teachers, It’s my great pleasure to be here sharing my lesson with you.The content of my lesson is Senior English Book 3 Unit 5 Canada —— “The true North”.I’ll be ready to begin this lesson from five parts. Analysis of the teaching material,the teaching methods,the studying methods, the teaching procedure,and Blackboard design.First, let me talk about the teaching material.Part 1 Teaching Material:This unit is about the introduction of Canada. By studying of this unit,we’ll enable the students to learn the geography, population, main cities, and natural beauty, natural resources of Canada. Through the training of the unit, it also requires students to learn some Language skills such as the expressions of position and emotions.So it plays an important part in the English teaching in this book.After studying the teaching material and analyzing the rule of children’s growing of mind,I think the teaching aims are the followings:1.Knowledge objects:(1) make the students learn some new words and phrases(2) make the students understand the content of the lesson.2.Ability objects:(1)To develop the Ss’ abilities of listening, speaking, reading and writing. Especially reading and speaking ability.(2) learn to talk about the characters of Canada in English(3)To train the Ss’ ability of working in pairs.3.Emotion objects:(1)Enable students to understand the characters of Canada..(2)Stimulate Ss to work hard to make China stronger.Part 2 Teaching Methods:I think helping students learn to master new words and phrases and improve the students’ reading and speaking ability is import and the difficult.According to the analysis of the teaching material and the import points and the difficult points,I will use the following teaching methods : question-guiding approach; fast-reading and careful reading; multi-media teaching methods; discussion
人教版高中英语必修4Women of achievement说课稿4篇
Good morning, distinguished judges:It’s my honor to talk about my teaching ideas with you. Today my topic is Women of Achievement. My presentation consists of six parts: the analysis of teaching material and student, teaching aims, key and difficult points, teaching and studying method, teaching procedures and blackboard design.First, let’s focus on the analysis of teaching material. This lesson is from New Senior English for China Student’s Book 4 Unit 1, the reading part. The main topic of the passage is the introduction of a student of Africanwildlife. After this lesson, the students will learn more information about her studying chimps in Africa, and their reading and speaking abilities can be developed as well.The next part is the analysis of students. My students are in senior high students. They have learnt English for many years, they’ve known many words and sentences, but their speaking and reading abilities are still not very good. So I will practice their speaking and reading abilities through different exercises.According to the New Standard Curriculum and the present situation, I set the teaching aims as follows: firstly, knowledge aims. Students can grasp some new words, such as worthwhile, move off. Moreover, students can understand the content of the passage and get familiar with the topic of studying chimps in wildlife. Secondly, ability aims. Students can use reading strategies such as skimming and scanning in reading process. Thirdly, emotional aims. Students can have the awareness of protecting animals and care about animals.Based on the above analysis, the key point of this lesson is to get the main idea and the detailed information from the passage; the difficult point is to talk about the wildlife protection and use reading strategies.
人教版高中英语必修3Festivals around the World说课稿3篇
Teaching plan for Unit 1 book3Good morning, teachers. It’s my great pleasure to be here because I can share my lesson with you and I can learn a lot from it. I’ll begin my lesson from the following four parts， the teaching material, the teaching methods, the studying methods and the teaching procedure.Firstly, let me talk about the teaching material. The content of my lesson is the reading passage festivals and celebrations of Unit 1 Festivals around the world. This passage is about festivals and celebrations. By studying this passage, we’ll enable the students to know that festivals exit everywhere, and many of festivals in different countries celebrate similar ideas. As we all know, the reading passage is the center of each unit. If the Ss can learn it well, it will be helpful to make the Ss learn the rest of this unit.After studying the teaching material, I think the teaching aims are as the followings:1. Knowledge aims:(1) The Ss can master the usage of the important words andexpressions.(2)The Ss can use the __________________ (grammar) in the proper situation.Make students know about the festivals all over the world and the detail of the festivals, such as origin, content, and the date of the holiday festivals.2. Ability aims:(1) Students can talk about festivals and celebrations in English(2) To improve the student’s reading ability, especially their skimming and scanning ability.3. Emotion aims:Make the Ss know about the foreign festivals, and respect other countries’ custom.Next, let’s come to the important points and the difficult points.The important point is how to make the Ss understand the text better and the difficult point is how can they talk about it. secondly， Teaching Methods:1. task-based Language Teaching2. Computer assisted language teaching.3. question-and–answer methodThirdly， Studying Methods:
人教版高中英语必修4Theme parks说课稿3篇
The oldest and the most popular park in the worldenjoy the exciting activities thereget close to the life-size cartoon characters like Mickey Mouse and Donald Duck Step 3 Pre-reading1.What do you suppose a theme park is ?2.What do you think you can see in a theme park?(1.It is a kind of amusement park which has a certain theme – that the whole park is based on. 2.buildings, castles, statues, rare animals and birds, and so on.) Step 4 Reading ----- Theme Parks –---- Fun and More Than Fun1.Predict : Read the title and the pictures on P. 34 and PredictWhat is the meaning of the title “Theme Park – Fun and more than fun”?(The title means that theme parks are fun to visit, but that they can also be educational and can offer useful information.)2.Skimming Fast read and answer:What activities can we take in a theme park?Amusement park: Bumper car Merry-go-round slide bungee jumping Free-fall rides Horror films Pirate ship Ferris wheel roller coaster3.Scanning Read again and you will find various theme parks are mentioned in the passage . Then what are they ?Theme parks: Sports theme park History theme park Culture theme park Marine or Ocean theme Park Future park Science theme park Disneyland4.Careful reading and find the main idea of each paragraph:THEME PARKS---- entertaining/ educationalPara.1 Traditional parks are places to go for relaxation and to have time away from our busy lives.Para.2 Theme parks are different They’re large and full of things to do, see and buy.Para.3 Theme parks are built around a single idea or theme. One example is a sports park.Para.4 Another kind of theme park is historical more and cultural and can be educational.Para.5 Disneylandwas the first theme park. It is based on the fantasy life and characters of Disney’s films.Para.6 Some examples of educational theme parks include sea world parks and science parks.
人教版高中英语必修4Working The Land说课稿3篇
Knowledge objectives:(1) to make Ss grasp the usage of words, expressions and sentence structures: statistics, struggle, thanks to, rid of, some patterns for persuasion, the “ing” form as subject and object;(2)to use learnt knowledge to persuade sb.Ability objectives:(1) to develop Ss’ reading skills(skimming, scanning, word guessing);(2) to improve Ss’ speaking, communicating and cooperating skills.Emotional objectives:to make Ss know the contribution of Yuan,and learn his spirit and his simple life time.Teaching important and difficult points:(1) some words, expressions and sentence structures mentioned above;(2)the content of the text;(3)training their reading and speaking skills.Teaching methods: CLT, TBLT,QT.Learning strategies: CLS, QLS, TBLS.Teaching procedures:Step 1 lead-in: (1) teacher plays a piece of recent news from CCTV about the harvest of the super hybrid rice, and ask students whether they know Yuan or not, and talk about him and his contribution.(2)Brain storm: let Ss describe Yuan in their minds including his appearance, his living condition and so on.Step 2 fast reading tasks:(1)teacher introduces Yuan and super hybrid rice(2)make Ss read the text as fast as possible with questions. Such as: what’s the general ideaof this passage? What’s Yuan’ dream? (skimming and scanning skill)Step 3 intensive reading tasks(1)let Ss read the text silently, find topic sentence of each paragraph and draw the difficult sentences and the knowledge what they don’t understand.(words guessing)(2)teacher and Ss talk about the important words, expressions and sentences together, and ask Ss to retell the content of the text.(summarizing and paraphrasing)(3)teacher summarize this part.(4) read again following the courseware.
人教版高中英语必修5Great scientists说课稿4篇
通过写文章梗概，培养学生综合运用语言的能力，学习用恰当的英语描述科学家的故事。这是本课的教学难点。教师可以使用完形填空的方式来帮助学生整理语篇，从而来降低难度。本课的教学重点的突破方法是：在阅读前，让学生初步了解得出科学观点所需要的基本程序，从而轻松而自然地导入文章的阅读；在阅读过程中，由易到难设计快速阅读和精读的问题，层层推进各种阅读活动，让学生对阅读内容从整体感知到细节理解，最后深层读懂整篇文章，同时加强阅读策略的指导，让每个学生都主动参与课堂教学活动，最终达到提高阅读能力的目的。Step 4 Post-readingGroup Activities四人小组共同合作，在老师的适当指导下，就以下2个问题展开讨论，让学生就所知、所学、所感和所想融入话题，然后抽若干同学代表作小组发言。1. What do you think about John Snow, and what should we learn from him?2. Cholera was 19th century disease, which two diseases are similar to cholera today? Why?