ch02 The world wide web
世界上最大的广域网是什么
世界上最大的广域网是什么1. 世界上最大的广域网是什么？因特网（Internet）2. 我国于哪年正式接入因特网？我国于1994年正式联入因特网3. 我国最早接入因特网的是什么单位？中国科学院高能物理所。
4. IP地址是由多少位二进制数组成，换算成字节是几个字节？32位，4个字节5. 在因特网上可以有重复的域名吗？不能6. 在INTERNET 网上计算机必须遵循什么网络协议？TCP/IP7. 上网浏览信息必须知道什么？网站的网址8. 因特网的英文名称是什么？Internet9. Internet的中文名称是什么？国际互联网或因特网10. 如果想保存你感兴趣的网页地址，可以使用IE浏览器中的什么菜单？“收藏”菜单11. 网络的域名地址中，有一部分代表国家，其中什么代表中国？ cn12. 网络的域名中，有一部分代表类型，代表教育机构站点的是什么？Edu13. Internet上计算机的名字由许多域构成，域间用什么符号分隔？小圆点14. 计算机网络最突出的优点是什么？连网的计算机能够相互共享资源15. 计算机系统是由什么组成？硬件系统和软件系统16. 为网络中各计算机之间交流信息提供统一的语言和规则的是什么？网络协议17. 要想查看近期访问的站点，应该点击IE浏览器的什么按钮？历史18. 用IE访问网页时，一般鼠标指针呈什么形状时才能点击鼠标访问网站里的信息？当鼠标变成手形时19. WWW的含义是什么？World Wide Web又称万维网20. 我们为每个IP地址规定一个英文代码，此代码一般称为什么？域名集体回答题（六道）：1. 说出至少两种常用的下载软件？a) 迅雷b) 影音传送带c) 网际快车d) 网络蚂蚁2. 说出至少2个搜索引擎？l 中文雅虎：l 网易：l 搜狐：l 搜狗：l 爱问：l 新浪: /l 百度：l Google: 3. 电子邮件有什么特点？电子邮件具有快速、高效、方便、价廉等特点4. 至少说出三种因特网提供的信息服务1）、发电子邮件(E―MAIL) 4）、信息查询与检索WWW 2）、文件传输（FTP） 5）、网络新闻（USENET）3）、远程登录（Telnet） 6）、电子公告板 (BBS)5. 说出至少域名中的三个部门代码？com 商业系统edu 教育系统gov 政府机关mil 军队系统net 网络管理部门org 非盈利性组织firm 商业或公司store 提供购买商品的业务部门web 主要活动与WWW有关的实体arts 以文化活为主的实体rec 以消遣性娱乐活动为主的实体inf 大量提供信息服务的实体nom 有针对性的人员或个人的命令AC 科研机构6. 说出至少3个域名中的国家代码？cn 中国au 澳大利亚de 德国uk 英国fr 法国it 意大利jp 日本抢答题（20题）：容易(6题)：1. 怎样保存网页上的某张图片？在图片处击右键→ “图片另存为”→ 选择图片存放的路径。
《计算机专业英语》The World Wide Web
Computer English Chapter 9 The World Wide WebRequirements:•理解万维网(World Wide Web)的工作原理；•能够描述Internet和万维网的特征及其服务；•了解学术论文写作的有关知识。
The invention of the Web brought an extraordinary expansion of digital services to millions of amateur computer users, including color text and pages, formatted text, pictures, animations, video, and sound. In short, the Web makes nearly all the rich elements of human expression needed to establish a commercial marketplace available to nontechnical computer users worldwide.万维网的发明带来了为数以百万计的业余计算机使用者提供的数字化服务的非常扩展,包括彩色文本和网页、格式化文本、图片、动画、视频和声音。
简而言之，万维网使建立商业化市场必需的人类表达方式的几乎所有丰富要素对非技术计算机使用者成为可能。
9.1 HYPERTEXTWeb pages can be accessed through the Internet because the Web browser software operating your PC can request Web pages stored on an Internet host server using the HTTP protocol. Hypertext is a way of formatting pages with embedded links that connect documents to one another, and that also link pages to other objects such as sound, video, or animation files. When you click on a graphic and a video clip plays, you have clicked on a hyperlink.因为操作个人计算机的网络浏览器软件能使用HTTP协议对储存在因特网主机服务器上的一个网页发出请求,所以能通过因特网访问万维网网页。
高考英语物理试卷
Part I Listening Comprehension (25 points)Section A (5 points)In this section, you will hear 5 short conversations. At the end of each conversation, a question will be asked about what was said. Both the conversation and the question will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices marked A), B), C) and D), and decide which is the best answer.1. A) He is going to have a meeting. B) He is going to have a rest.C) He is going to take a break. D) He is going to take a vacation.2. A) She has finished her homework. B) She has lost her book.C) She has found her book. D) She has finished her assignment.3. A) He doesn't like playing basketball. B) He is good at playing basketball.C) He doesn't play basketball. D) He is going to play basketball.4. A) She doesn't like tea. B) She prefers coffee to tea.C) She likes both tea and coffee. D) She prefers tea to coffee.5. A) She will go to the library. B) She will go to the bookstore.C) She will go to the cinema. D) She will go to the park.Section B (20 points)In this section, you will hear a passage three times. When the passageis read for the first time, you should listen carefully for general ideas. When the passage is read for the second time, you are required to fill in the blanks with the exact words you have just heard in the blanks provided. When the passage is read for the third time, you should check what you have written.One of the most important discoveries in physics was made by a British scientist named Michael Faraday. He was born in 1791 and died in 1867.Faraday was interested in science from a young age and became ascientist by accident. He was working as a bookbinder in a bookstore when he met a famous scientist named Humphry Davy. Davy was impressed with Faraday's curiosity and intelligence, and he encouraged him to study science.Faraday began to study chemistry and physics. He was particularly interested in electricity and magnetism. In 1821, he discovered that a current of electricity passing through a wire can create a magnetic field. This discovery led to the development of electric motors and generators. In 1831, Faraday discovered that a changing magnetic field can produce an electric current. This discovery led to the development of transformers and generators.Faraday's work had a profound impact on the field of physics. He was able to explain many of the phenomena that had been observed in electricity and magnetism. His work also laid the foundation for many of the technologies that we use today. Faraday was a remarkable scientist who made significant contributions to the field of physics.Part II Structure and Vocabulary (25 points)Section A (15 points)There are 15 sentences in this section. Each sentence has one underlined word or phrase. Choose the one from the four options that best keeps the meaning of the sentence.1. A) destroyed B) destroyed C) destroyed D) destroyed2. A) studying B) studying C) studying D) studying3. A) discovered B) discovered C) discovered D) discovered4. A) influenced B) influenced C) influenced D) influenced5. A) established B) established C) established D) established6. A) contributed B) contributed C) contributed D) contributed7. A) influenced B) influenced C) influenced D) influenced8. A) contributed B) contributed C) contributed D) contributed9. A) established B) established C) established D) established10. A) discovered B) discovered C) discovered D) discovered11. A) influenced B) influenced C) influenced D) influenced12. A) contributed B) contributed C) contributed D) contributed13. A) established B) established C) established D) established14. A) discovered B) discovered C) discovered D) discovered15. A) influenced B) influenced C) influenced D) influencedSection B (10 points)Complete the following sentences with the appropriate forms of the words given in brackets.1. The experiment (repeat) many times to ensure its accuracy.2. The scientist (discover) a new element in 1898.3. The invention of the light bulb (change) our lives forever.4. The theory of relativity (propose) by Einstein in 1905.5. The solar system (form) about 4.6 billion years ago.Part III Reading Comprehension (30 points)Section A (10 points)Read the following passage and answer the questions that follow.The World Wide Web (WWW) is a vast collection of documents and other resources, primarily text, images, and sound, stored on computers all over the world. It is accessed through the Internet. The World Wide Web is a powerful tool for communication, education, and entertainment.The World Wide Web was created by Tim Berners-Lee in 1989. He was working at CERN, the European Particle Physics Laboratory, when he cameup with the idea of a hypertext system that could be used to share information. Berners-Lee developed the HTML (Hypertext Markup Language) and HTTP (Hypertext Transfer Protocol) protocols, which are used to create and display web pages.Today, the World Wide Web is used by millions of people around the world. It has become an integral part of our daily lives. We use it to access information, communicate with others, and entertain ourselves. The World Wide Web has also had a significant impact on education and business.Questions:1. What is the World Wide Web?2. Who created the World Wide Web?3. What are two uses of the World Wide Web?4. What are the two protocols used to create and display web pages?Section B (20 points)Read the following passage and answer the questions that follow.The study of physics is essential to understanding the world around us. Physics is the science of matter and energy. It seeks to explain the fundamental laws of nature and how they affect the universe.Physics has many branches, including mechanics, thermodynamics, electromagnetism, and quantum mechanics. Each branch of physics studies a different aspect of matter and energy. Mechanics, for example, studies the motion of objects. Thermodynamics studies the transfer of heat and energy. Electromagnetism studies electric and magnetic fields. Quantum mechanics studies the behavior of particles at the atomic and subatomic levels.Physics has had a profound impact on our lives. It has led to the development of many technologies, such as electricity, computers, and medical imaging. Physics has also helped us understand the universe,from the smallest particles to the largest galaxies.Questions:1. What is the main focus of physics?2. Name three branches of physics.3. How has physics impacted our lives?4. What is the significance of physics in understanding the universe?Part IV Writing (25 points)Write an essay of about 150-200 words on the following topic:How has technology changed our lives in the last 50 years?You should use your own ideas, knowledge, and experience to support your essay.Remember to:1. Write an essay in an organized manner.2. Use a variety of sentence structures.3. Use appropriate vocabulary.[Answer space provided]。
互联网（internet）、因特网（Internet）、万维网（WorldWideWeb）三者区别
互联⽹（internet）、因特⽹（Internet）、万维⽹（WorldWideWeb）三者区别互联⽹（internet）互联⽹是指多台设备（如计算机、⼿机等）通过特定通信协议（TCP/IP、IPX/SPX、NetBIOS、NetBEUI、Apple Talk）组成的⽹络。
⼀般可分为以下三种：局域⽹局域⽹LAN(Local Area Network)：⼀般不⼤于10公⾥，⽽且通常只使⽤⼀种传输介质；地域上看局域⽹通常是⽤在⼀座建筑物或⼀个⼯⼚内，使⽤上通常是某⼀单位或某⼀部门使⽤，规模上⼀般不超过⼏百个⽤户。
城域⽹城域⽹MAN(Metropolitan Area Network)：城域⽹是⼀种⽐局域⽹更⼤的⽹，通常覆盖⼀个城市，从⼏⼗公⾥到100公⾥不等，可能会有多种介质，⽤户的数⽬也⽐局域⽹更多。
⼴域⽹⼴域⽹WAN(Wide Area Network)：⼀切⼤于城域⽹的⽹都可称为⼴域⽹。
不同的局域⽹、城域⽹或⼴域⽹还可以根据需要互相链接构成规模更⼤的国际⽹。
因特⽹（Internet）因特⽹是由上千万台设备组成的⽹络（⼀般指具有⼀定规模的⽹络）。
因特⽹使⽤TCP/IP协议让不同设备彼此通信。
设备接⼊因特⽹需要满⾜两个要求，⾸先⽹络设备必须安装TCP/IP协议，⽤于和因特⽹的其他⽹络设备通信；其次必须具备⼀个公⽹地址，⽤于在因特⽹中标记该设备，使得因特⽹的其他⽹络设备能将其定位。
万维⽹（World Wide Web）万维⽹是基于因特⽹，通过TCP/IP应⽤层协议中的HTTP协议提供的服务，浏览器使⽤HTTP协议与服务器进⾏通信，发送数据请求，获取HTML⽂件，再通过浏览器解析，最终以⽹页的形式呈现给⽤户。
三者联系互联⽹ > 因特⽹ > 万维⽹只要多台设备之间可以通过特定的通信协议进⾏通信，它们便组成了⼀个互联⽹。
因特⽹中的设备则必须使⽤TCP/IP协议通信，且要构成⼀定规模的⽹络（包含若⼲⼦⽹络），不同⼦⽹络必须具备⾃⼰的公⽹地址。
万维网创始人
万维网创始人作者：王立来源：《七彩语文·中高年级》2013年第03期当你上网的时候，你会发现大部分网址的开头总有三个字母“www”。
这三个“w”，即“World Wide Web”的英文缩写，中文意思是万维网。
万维网的发明者叫蒂姆·伯纳斯·李，他曾获得首届“千禧年技术奖”。
千禧年技术奖：2002年创立，自2004年起每隔两年举办一次，目的是奖励在科学技术领域和IT界中有重大贡献的人物，被誉为“工程界的诺贝尔奖”。
虽然伦敦奥运会已经结束，但那充满英国元素的奥运会开幕式，给全世界留下了深刻印象。
如果你观看过伦敦奥运会开幕式，那么，你有没有注意到这样一幕：会场的灯光变暗了，观众渐渐地安静下来，所有人的目光聚集到侧舞台上，一位英国科学家独自坐在一台老式电脑前，通过电脑向全世界的观众发出一条英文信息：This is for everyone（这是为了所有人），随后全场观众报以热情的掌声。
这位受到热烈欢迎的科学家是谁呢？其实，他的名字被巧妙地藏在开幕式这部分的主题名“感谢蒂姆”中。
蒂姆就是这位科学家的名字，全名是蒂姆·伯纳斯·李。
在世界瞩目的奥运会开幕式上，特意安排独立环节，向一位科学家表示感谢和敬意，在奥运会历史上是很少见的。
那么，为什么要感谢蒂姆呢？因为他发明了万维网，并创造了世界上第一个网站和第一个网页浏览器。
毫不夸张地说，没有蒂姆的发明，就没有今天人们常用的互联网。
凭借这项发明，蒂姆在2004年获得了千禧年技术奖。
他在颁奖仪式上谦虚地说：“我并不是完全靠自己建成了万维网。
万维网最让人激动之处就在于它是很多很多人，靠着巨大的精神作用联系在一起做成的。
”对于他的谦虚，颁奖委员会主席佩卡·塔里扬内说：“没有人怀疑万维网之父是谁，除了蒂姆自己。
”蒂姆的成功来源于他从小对电脑的热爱。
小时候，蒂姆身边的小朋友喜欢用纸来叠飞机、帆船。
但蒂姆不一样，他最爱做的是，在小卡纸上打孔，然后试着把这些卡纸拼成电脑的样子。
人教版高一英语入学摸底考试
人教版高一英语入学摸底考试8. What problem did the man have with his phone?A. The battery was low.B. The screen was cracked.C. The camera didn’t work.9. What did the man do to solve the problem?A. He bought a new phone.B. He took it to a repair shop.C. He restarted the phone.听第8段材料，回答第10~12小题。
10. What is the man’s job?A. A teacher.B. A doctor.C. A businessman.11. How does the man feel about his job?A. He enjoys it.B. He hates it.C. He is indifferent.12. What does the woman suggest the man do?A. Take a vacation.B. Quit his job.C. Work harder.听第9段材料，回答第13~15小题。
13. What is the woman’s problem?A. She can’t find her passport.B. She missed her flight.C. She lost her luggage.14. What does the man suggest the woman do?A. Go to the airline’s office.B. Bu y a new ticket.C. Wait for the next flight.15. What is the relationship between the man and the woman?A. They are strangers.B. They are colleagues.C. They are friends.第二部分：阅读理解（共两节，满分40分）第一节（共15小题；每小题2分，满分30分）AThe History of the InternetThe Internet is the modern engine of progress and has had a far more rapid and profound effect on our daily lives than the industrial revolution. But where did it come from?The idea of an interconnected network of computers was first thought of in the early 1960s by J.C.R. Licklider, who was the first director of the Information Processing Technology Office (IPTO) at the US Defense Department’s Advanced Research Projects Agency (ARPA). He envisioned a globally interconnected set of computers through which everyone could quickly access data and programs from any site.In the late 1960s, the US Defense Department’s Advanced Research Projects Agency Network (ARPANET) was created to allow scientists to share data and information. ARPANET was the first wide-area network to use packet switching, a method of transmitting electronic data that would later become one of the major building blocks of the Internet.The first email was sent in 1971 by Ray Tomlinson, who is credited with inventing email. The first domain name was registered in 1985, and the first website was created three years later.The World Wide Web was invented in 1989 by Tim Berners-Lee, a British computer scientist. He created the first web browser and web server in 1990. The first search engine, Archie, was created in 1990, followed by Yahoo! in 1994 and Google in 1998.The Internet has since grown beyond anyone’s expectations, and its impact on society has been immeasurable. It has revolutionized the way we communicate, work, and even think. It has brought the world closer together and made information more accessible than ever before.16. Who first thought of the idea of an interconnected network of computers?A. Tim Berners-Lee.B. Ray Tomlinson.C. J.C.R. Licklider.17. What was the first wide-area network to use packet switching?A. ARPANET.B. Yahoo!.C. Google.18. When was the World Wide Web invented?A. 1960s.B. 1971.C. 1989.19. What was the first search engine?A. Archie.B. Yahoo!.C. Google.20. Which of the following is NOT true about the impact of the Internet on society?A. It has revolutionized the way we communicate.B. It has brought the world closer together.C. It has made information less accessible than ever before.D. It has changed the way we work and think.BThe Benefits of ReadingReading is g ood for you. It’s a fact. But why? Here are some of the benefits of reading that you may not have known.1. Reading makes you more empathetic.When you read, you put yourself in the shoes of the characters. You see the world from their perspective. This helps you to understand other people’s feelings and experiences, and makes you more empathetic.2. Reading improves your vocabulary.The more you read, the more words you are exposed to. This helps to expand your vocabulary and improve your communication skills.3. Reading reduces stress.Reading is a great way to relax and unwind. It can help to reduce stress and anxiety, and promote mental clarity and focus.4. Reading improves your memory.When you read, you exercise your brain. This helps to improve your memory and cognitive function.5. Reading can help you sleep better.Reading before bed can help to calm your mind and prepare you for sleep. It’s a great alternative to watching TV or using your phone, which can actually disrupt your sleep patterns.So there you have it. Reading is good for you. Whether you’re reading a book, a magazine, or a newspaper, it’s a great way to improve your mental health and well-being.21. What is one benefit of reading that the passage mentions?A. It improves your communication skills.B. It reduces stress and anxiety.C. It helps you to see the world from other people’s perspective.D. It helps you to exercise your brain.22. What is another benefit of reading that the passage mentions?A. It can help you to sleep better.B. It can help you to reduce stress and anxiety.C. It can help you to improve your cognitive function.D. It can help you to expand your vocabulary.23. What is the main idea of the passage?A. Reading is a great way to improve your mental health and well-being.B. Reading can help you to exercise your brain and improve your memory.C. Reading can help you to see the world from other people’s perspective and improve your communication skills.D. Reading is good for you in many ways, including reducing stress, improving your vocabulary, and helping you to sleep better.CThe Benefits of YogaYoga is a popular form of exercise that has been around for thousands of years. It originated in India and has since spread all over the world. Here are some of the benefits of practicing yoga.1. It improves flexibility.Yoga involves stretching and holding poses for extended periods of time. This helps to improve flexibility and range of motion.2. It strengthens muscles.Many yoga poses require you to support your own body weight, which helps to build strength and tone muscles.3. It reduces stress and anxiety.Yoga is a great way to relax and unwind. It can help to reduce stress and anxiety, and promote a sense of calm and well-being.4. It improves balance and coordination.Many yoga poses require you to balance on one leg or support your body weight with your arms. This helps to improve balance and coordination.5. It promotes mindfulness.Yoga involves focusing on your breath and being present in the moment. This helps to promote mindfulness and reduce distractions.So there you have it. Yoga is a great way to improve your physical and mental health. Whether you’re a beginner or an experienced yogi, there are many benefits to practicing yoga.24. What is one benefit of practicing yoga that the passage mentions?A. It improves flexibility and range of motion.B. It helps to build strength and tone muscles.C. It reduces stress and anxiety.D. It helps to improve balance and coordination.25. What is another benefit of practicing yoga that the passage mentions?A. It promotes mindfulness and reduces distractions.B. It helps to improve range of motion and tone muscles.C. It reduces stress and anxiety and promotes a sense of calm.D. It helps to improve balance and coordination and strengthens muscles.26. What is the main idea of the passage?A. Yoga is a popular form of exercise that has many benefits for physical and mental health.B. Yoga originated in India and has since spread all over the world.C. Yoga is a great way to improve flexibility and range of motion.D. Yoga is a great way to reduce stress and anxiety.B. They suspected the man of stealing.C. They needed the man's help in finding something.16. What did the man find out about the hole?A. It was caused by a construction accident.B. It was a natural sinkhole.C. It was dug by someone intentionally.Rewritten:8. The woman had a stroke of bad luck because her car was scratched badly, and she was late for work this morning. She did not mention being injured in an accident.9. The news that the speakers read about was a bus crash that resulted in the death of forty people.10. The man asked about the nationality of Joan's husband and gave three options: Japanese, Chinese, and Greek. The correct answer was not given in the recording.11. The man knew that Joan had got married because Joan told him by email.12. The woman will probably call Joan when she gets home.13. The funny thing that the man mentioned took place one late afternoon.14. The man went home to fetch a long rope.15. The police took the man to the police station because they suspected him of stealing something related to the hole.16. The man found out that the hole was a natural sinkhole, not caused by construction or dug intentionally.Rewritten:New York is a well-organized city with straight streets running north and south or east and west. The streets are numbered and the avenues are named after American states, with Fifth Avenue being the most famous. Skyscrapers like the Empire State Building and the Chrysler Building are iconic landmarks of the city. Central Park is a popular park in the heart of Manhattan, covering 843 acres and offering many recreational activities. Broadway and Times Square are famous for theaters, shows, and bright lights. The city also boasts many museums, such as the Metropolitan Museum of Art and the American Museum of Natural History. New York is a vibrant city with endless attractions to explore.21. In the second sentence of the passage, "laid out" means designed.22. The streets running from north to south are called avenues in New York City.In conclusion, while the use of wild animals in circuses may be controversial, it is important for us to consider the safety of all involved. Whether or not circuses continue to use animals in their shows, it is important for them to take every measure to ensure the safety of both the animals and the performers.It's frustrating that while experts debate about which option is best, people who want to improve their lives are left confused by conflicting information. This can make us feel like we can't focus, or that we're focused on the wrong things. As a result, we take less action, make less progress, and remain stagnant instead of improving.In paragraph 3, the author mentions experts who claim that success is determined by factors such as genetics, upbringing, or luck. However, the author is doubtful of such claims and believes that success is largely determined by one's own actions and choices.Thangmi with an Ethnolinguistic Introduction to the Speakers and Their Culture, is a comprehensive study of the Thangmi language spoken in Nepal, India, and Bhutan. The book not only provides a grammar of the language but also explores the cultureand history of the Thangmi people. Turin hopes that his work will contribute to the preservation of the Thangmi language and culture.The loss of languages not only means the loss of cultural diversity but also the loss of knowledge and wisdom accumulated over centuries. Languages are not just a means of communication but also a repository of a community's history, traditions, and beliefs. When a language dies, a whole world of knowledge and experience disappears with it.Therefore, it is important to recognize the value of linguistic diversity and take measures to preserve endangered languages. This can be done through documentation, language revitalization programs, and education. By preserving languages, we can also preserve the cultural heritage and identity of communities around the world.Overall, Thangmi is an important contribution to the preservation of the Thangmi people's language and culture, as wellas other oral traditions in the Himalayan region. Through his work, Turin hopes to ensure that these voices are not lost to history.。
The World Wide Web
• The terms Internet and World Wide Web are often used in everyday speech without much distinction. However, the Internet and the World Wide Web are not one and the same. The Internet is a global system of interconnected computer networks. In contrast, the Web is one of the services that runs on the Internet. It is a collection of text documents and other resources, linked by hyperlinks and URLs, usually accessed by web browsers from web servers. In short, the Web can be thought of as an application"running" on the Internet.
• When you type an Internet site ,firstly you are bound to type three letters ‘www’.Do you ever doubt of its meaning?Actually, it is the abbreviation of the words ‘world wide web’.Ok ,today ,I will introduce it to you in detail.
• 1. broaden our horizons • 2.make it easy to communicate with the outside world • 3.provide considerable information • 4.make our life more convenient
World-Wide-Web
World Wide WebThe World Wide Web (commonly abbreviated as "the Web") is a system of interlinked hypertext documents accessed via the Internet. With a Web browser, one can view Web pages that may contain text, images, videos, and other multimedia and navigate between them using hyperlinks. Using concepts from earlier hypertext systems, the World Wide Web was started in 1989 by the English physicist Sir Tim Berners-Lee, now the Director of the World Wide Web Consortium, and later by Robert Cailliau, a Belgian computer scientist, while both were working at CERN in Geneva, Switzerland. In 1990, they proposed building a "web of nodes" storing "hypertext pages" viewed by "browsers" on a network, and released that web in December. Connected by the existing Internet, other websites were created, around the world, adding international standards for domain names & the HTML language. Since then, Berners-Lee has played an active role in guiding the development of Web standards (such as the markup languages in which Web pages are composed), and in recent years has advocated his vision of a Semantic Web.The World Wide Web enabled the spread of information over the Internet through an easy-to-use and flexible format. It thus played an important role in popularizing use of the Internet. Although the two terms are sometimes conflated in popular use, World Wide Web is not synonymous with Internet. The Web is an application built on top of the Internet.HistoryIn March 1989, Berners-Lee wrote a proposal which referenced ENQUIRE and described a more elaborate information management system. With help from Robert Cailliau, he published a more formal proposal (on November 12, 1990) to build a "Hypertext project" called "WorldWideWeb" (one word, also "W3") as a "web of nodes" with "hypertext documents" to store data. That data would be viewed in "hypertext pages" (webpages) by various "browsers" (line-mode or full-screen) on the computer network, using an "access protocol" connecting the "Internet and DECnet protocol worlds".The proposal had been modeled after EBT's (Electronic Book Technology, a spin-off from the Institute for Research in Information and Scholarship at Brown University) Dynatext SGML reader that CERN had licensed. The Dynatext system, although technically advanced (a key player in the extension of SGML ISO 8879:1986 to Hypermedia within HyTime), was considered too expensive and with an inappropriate licensing policy for general HEP (High Energy Physics) community use: a fee for each document and each time a document was changed.A NeXT Computer was used by Berners-Lee as the world's first Web server and also to write the first Web browser, WorldWideWeb, in 1990. By Christmas 1990, Berners-Lee had built all the tools necessary for a working Web: the first Web browser (which was a Web editor as well), the first Web server, and the first Web pages which described the project itself.On August 6, 1991, he posted a short summary of the World Wide Web project on the alt.hypertext newsgroup. This date also marked the debut of the Web as a publicly available service on the Internet.The first server outside Europe was set up at SLAC in December 1991.The crucial underlying concept of hypertext originated with older projects from the 1960s, such as the Hypertext Editing System (HES) at Brown University--- among others Ted Nelson and Andries van Dam--- Ted Nelson's Project Xanadu and Douglas Engelbart's oN-Line System (NLS). Both Nelson and Engelbart were in turn inspired by Vannevar Bush's microfilm-based "memex," which was described in the 1945 essay "As We May Think".Berners-Lee's breakthrough was to marry hypertext to the Internet. In his book Weaving The Web, he explains that he had repeatedly suggested that a marriage between the two technologies was possible to members of both technical communities, but when no one took up his invitation, he finally tackled the project himself. In the process, he developed a system of globally unique identifiers for resources on the Web and elsewhere: the Uniform Resource Identifier.The World Wide Web had a number of differences from other hypertext systems that were then available. The Web required only unidirectional links rather than bidirectional ones. This made it possible for someone to link to another resource without action by the owner of that resource. It also significantly reduced the difficulty of implementing Web servers and browsers (in comparison to earlier systems), but in turn presented the chronic problem of link rot. Unlike predecessors such as HyperCard, the World Wide Web was non-proprietary, making it possible to develop servers and clients independently and to add extensions without licensing restrictions.On April 30, 1993, CERN announced that the World Wide Web would be free to anyone, with no fees due. Coming two months after the announcement that the Gopher protocol was no longer free to use, this produced a rapid shift away from Gopher and towards the Web. An early popular Web browser was ViolaWWW, which was based upon HyperCard.Scholars generally agree that a turning point for the World Wide Web began with the introduction of the Mosaic Web browser in 1993, a graphical browser developed by a team at the National Center for Supercomputing Applications at the University ofIllinois at Urbana-Champaign (NCSA-UIUC), led by Marc Andreessen. Funding for Mosaic came from the U.S. High-Performance Computing and Communications Initiative, a funding program initiated by the High Performance Computing and Communication Act of 1991, one of several computing developments initiated by U.S. Senator Al Gore. Prior to the release of Mosaic, graphics were not commonly mixed with text in Web pages, and its popularity was less than older protocols in use over the Internet, such as Gopher and Wide Area Information Servers (WAIS). Mosaic's graphical user interface allowed the Web to become, by far, the most popular Internet protocol.The World Wide Web Consortium (W3C) was founded by Tim Berners-Lee after he left the European Organization for Nuclear Research (CERN) in October, 1994. It was founded at the Massachusetts Institute of Technology Laboratory for Computer Science (MIT/LCS) with support from the Defense Advanced Research Projects Agency (DARPA)—which had pioneered the Internet—and the European Commission.By the end of 1994, while the total number of websites was still minute compared to present standards, quite a number of notable websites were already active, many of whom are the precursors or inspiring examples of today's most popular services.How it worksThe terms Internet and World Wide Web are often used in every-day speech without much distinction. However, the Internet and the World Wide Web are not one and the same. The Internet is a global data communications system. It is a hardware and software infrastructure that provides connectivity between computers. In contrast, the Web is one of the services communicated via the Internet. It is a collection of interconnected documents and other resources, linked by hyperlinks and URLs. In short, the Web is an application running on the Internet.Viewing a Web page on the World Wide Web normally begins either by typing the URL of the page into a Web browser, or by following a hyperlink to that page or resource. The Web browser then initiates a series of communication messages, behind the scenes, in order to fetch and display it.First, the server-name portion of the URL is resolved into an IP address using the global, distributed Internet database known as the domain name system, or DNS. This IP address is necessary to contact the Web server. The browser then requests the resource by sending an HTTP request to the Web server at that particular address. In the case of a typical Web page, the HTML text of the page is requested first and parsed immediately by the Web browser, which then makes additional requests for images and any other files that form parts of the page. Statistics measuring a website'spopularity are usually based either on the number of 'page views' or associated server 'hits' () that take place.Having received the required files from the Web server, the browser then renders the page onto the screen as specified by its HTML, CSS, and other Web languages. Any images and other resources are incorporated to produce the on-screen Web page that the user sees.Most Web pages will themselves contain hyperlinks to other related pages and perhaps to downloads, source documents, definitions and other Web resources. Such a collection of useful, related resources, interconnected via hypertext links, is what was dubbed a "web" of information. Making it available on the Internet created what Tim Berners-Lee first called the WorldWideWeb (in its original CamelCase, which was subsequently discarded) in November 1990.Ajax updatesJavaScript is a scripting language that was initially developed in 1995 by Brendan Eich, then of Netscape, for use within Web pages. The standardized version is ECMAScript. To overcome some of the limitations of the page-by-page model described above, some web applications also use Ajax (asynchronous JavaScript and XML). JavaScript is delivered with the page that can make additional HTTP requests to the server, either in response to user actions such as mouse-clicks, or based on lapsed time. The server's responses are used to modify the current page rather than creating a new page with each response. Thus the server only needs to provide limited, incremental information. Since multiple Ajax requests can be handled at the same time, users can interact with a page even while data is being retrieved. Some web applications regularly poll the server to ask if new information is available.in Web addressesMany Web addresses begin with www, because of the long-standing practice of naming Internet hosts (servers) according to the services they provide. So, the host name for a web server is often it is an , and news or nntp for a USENET news server etc. These host names then appear as DNS subdomain names, as in "".The use of such subdomain names is not required by any technical or policy standard; indeed, the first ever web server was called "nxoc01.cern.ch", and many web sites exist without a prefix, or with some other prefix such as "www2", "secure" etc. These subdomain prefixes have no consequence; they are simply chosen names. Many web servers are set up such that both the domain by itself (e.g., ) and the (e.g., ) refer to the same site, others require one form or the other, or they may map to different web sites.When a single word is typed into the address bar and the return key is pressed, some web browsers automatically try adding "www." to the beginning of it and possibly ".com", ".org" and ".net" at the end. For example, typing 'microsoft<return>' may resolve to and 'openoffice<return>' to . This feature was beginning to be included in early versions of Mozilla Firefox (when it still had the working title 'Firebird') in early 2003. It is reported that Microsoft was granted a US patent for the same idea in 2008, but only with regard to mobile devices.The 'http://' or 'https://' part of web addresses does have meaning: These refer to Hypertext Transfer Protocol and to HTTP Secure and so define the communication protocol that will be used to request and receive the page and all its images and other resources. The HTTP network protocol is fundamental to the way the World Wide Web works, and the encryption involved in HTTPS adds an essential layer if confidential information such as passwords or bank details are to be exchanged over the public internet. Web browsers often prepend this 'scheme' part to URLs too, if it is omitted. In overview, RFC 2396 defined web URLs to have the following form:<scheme>://<path>?<query>#<fragment>.Pronunciation of "www"In English, pronounced by individually pronouncing the name of characters (double-u double-u double-u). Although some technical users pronounce itdub-dub-dub this is not widespread. The English writer Douglas Adams once quipped:The World Wide Web is the only thing I know of whose shortened form takes three times longer to say than what it's short for.– Douglas Adams, The Independent on Sunday, 1999It is also interesting that in Mandarin Chinese, World Wide Web is commonly translated via a phono-semantic matching to wàn wéi wǎng (万维网), which satisfies literally means "myriad dimensional net",a translation that very appropriately reflects the design concept and proliferation of the World Wide Web.Tim Berners-Lee's web-space states that World Wide Web is officially spelled as three separate words, each capitalized, with no intervening hyphens. Additionally, Web (with a capital W) is used to indicate its status as an abbreviation.StandardsMany formal standards and other technical specifications define the operation of different aspects of the World Wide Web, the Internet, and computer informationexchange. Many of the documents are the work of the World Wide Web Consortium (W3C), headed by Berners-Lee, but some are produced by the Internet Engineering Task Force (IETF) and other organizations.Usually, when Web standards are discussed, the following publications are seen as foundational:•Recommendations for markup languages, especially HTML and XHTML, from the W3C.These define the structure and interpretation of hypertext documents.•Recommendations for stylesheets, especially CSS, from the W3C.•Standards for ECMAScript (usually in the form of JavaScript), from Ecma International.•Recommendations for the Document Object Model, from W3C.Additional publications provide definitions of other essential technologies for the World Wide Web, including, but not limited to, the following:•Uniform Resource Identifier (URI), which is a universal system for referencing resources on the Internet, such as hypertext documents and images. URIs, often called URLs, aredefined by the IETF's RFC 3986 / STD 66: Uniform Resource Identifier (URI): GenericSyntax, as well as its predecessors and numerous URI scheme-defining RFCs;•HyperText Transfer Protocol (HTTP), especially as defined by RFC 2616: HTTP/1.1 and RFC 2617: HTTP Authentication, which specify how the browser and server authenticate each other.PrivacyComputer users, who save time and money, and who gain conveniences and entertainment, may or may not have surrendered the right to privacy in exchange for using a number of technologies including the Web. Worldwide, more than a half billion people have used a social network service, and of Americans who grew up with the Web, half created an online pro are part of a generational shift that could be changing norms. Facebook progressed from U.S. college students to a 70% non-U.S. audience and estimates that only 20% of its members use privacy settings.Privacy representatives from 60 countries have resolved to ask for laws to complement industry self-regulation, for education for children and other minors who use the Web, and for default protections for users of social networks. They also believe data protection for personally identifiable information benefits business more than the sale of that information. Users can opt-in to features in browsers to clear their personal histories locally and block some cookies and advertising networks but they are still tracked in websites' server logs, and particularly Web beacons. Berners-Lee and colleagues see hope in accountability and appropriate use achieved by extending the Web's architecture to policy awareness, perhaps with audit logging, reasoners and appliances.Among services paid for by advertising, Yahoo! could collect the most data about users of commercial websites, about 2,500 bits of information per month about each typical user of its site and its affiliated advertising network sites. Yahoo! was followed by MySpace with about half that potential and then by AOL-TimeWarner, Google, Facebook, Microsoft, and eBay.SecurityThe Web has become criminals' preferred pathway for spreading malware. Cybercrime carried out on the Web can include identity theft, fraud, espionage and intelligence gathering. Web-based vulnerabilities now outnumber traditional computer security concerns, and as measured by Google, about one in ten Web pages may contain malicious code. Most Web-based attacks take place on legitimate websites, and most, as measured by Sophos, are hosted in the United States, China and Russia.The most common of all malware threats is SQL injection attacks against websites. Through HTML and URIs the Web was vulnerable to attacks like cross-site scripting (XSS) that came with the introduction of JavaScript and were exacerbated to some degree by Web 2.0 and Ajax web design that favors the use of scripts. Today by one estimate, 70% of all websites are open to XSS attacks on their users.Proposed solutions vary to extremes. Large security vendors like McAfee already design governance and compliance suites to meet post-9/11 regulations, and some, like Finjan have recommended active real-time inspection of code and all content regardless of its source. Some have argued that for enterprise to see security as a business opportunity rather than a cost center, "ubiquitous, always-on digital rights management" enforced in the infrastructure by a handful of organizations must replace the hundreds of companies that today secure data and networks. Jonathan Zittrain has said users sharing responsibility for computing safety is far preferable to locking down the Internet.AccessibilityAccess to the Web is for everyone regardless of disability including visual, auditory, physical, speech, cognitive, and neurological. Accessibility features also help others with temporary disabilities like a broken arm and an aging population as their abilities change. The Web is used for receiving information as well as providing information and interacting with society, making it essential that the Web be accessible in order to provide equal access and equal opportunity to people with disabilities.The power of the Web is in its universality. Access by everyone regardless of disability is an essential aspect. —Tim Berners-LeeMany countries regulate web accessibility as a requirement for websites. International cooperation in the W3C Web Accessibility Initiative led to simple guidelines that Web content authors as well as software developers can use to make the Web accessible to persons who may or may not be using assistive technology.InternationalizationThe W3C Internationalization Activity assures that Web technology will work in all languages, scripts, and cultures. Beginning in 2004 or 2005, Unicode gained ground and eventually in December 2007 surpassed both ASCII and Western European as the Web's most frequently used character encoding. Originally RFC 3986 allowed resources to be identified by URI in a subset of US-ASCII. RFC 3987 allows more characters—any character in the Universal Character Set—and now a resource can be idenfified by IRI in any language.StatisticsAccording to a 2001 study, there were massively more than 550 billion documents on the Web, mostly in the invisible Web, or deep Web. A 2002 survey of 2,024 million Web pages determined that by far the most Web content was in English: 56.4%; next were pages in German (7.7%), French (5.6%), and Japanese (4.9%). A more recent study, which used Web searches in 75 different languages to sample the Web, determined that there were over 11.5 billion Web pages in the publicly indexable Web as of the end of January 2005. As of March 2009, the indexable web contains at least 25.21 billion pages. On July 25, 2008, Google software engineers Jesse Alpert and Nissan Hajaj announced that Google Search had discovered one trillion unique URLs. As of May 2009, over 109.5 million websites operated. Of these 74% were commercial or other sites operating in the .com generic top-level domain.Speed issuesFrustration over congestion issues in the Internet infrastructure and the high latency that results in slow browsing has led to an alternative, pejorative name for the World Wide Web: the World Wide Wait. Speeding up the Internet is an ongoing discussion over the use of peering and QoS technologies. Other solutions to reduce the World Wide Wait can be found at W3C.Standard guidelines for ideal Web response times are:•0.1 second (one tenth of a second). Ideal response time. The user doesn't sense any interruption.• 1 second. Highest acceptable response time. Download times above 1 second interrupt the user experience.•10 seconds. Unacceptable response time. The user experience is interrupted and the user is likely to leave the site or system.CachingIf a user revisits a Web page after only a short interval, the page data may not need to be re-obtained from the source Web server. Almost all Web browsers cacherecently-obtained data, usually on the local hard drive. HTTP requests sent by a browser will usually only ask for data that has changed since the last download. If the locally-cached data are still current, it will be reused.Caching helps reduce the amount of Web traffic on the Internet. The decision about expiration is made independently for each downloaded file, whether image, stylesheet, JavaScript, HTML, or whatever other content the site may provide. Thus even on sites with highly dynamic content, many of the basic resources only need to be refreshed occasionally. Web site designers find it worthwhile to collate resources such as CSS data and JavaScript into a few site-wide files so that they can be cached efficiently. This helps reduce page download times and lowers demands on the Web server. There are other components of the Internet that can cache Web content. Corporate and academic firewalls often cache Web resources requested by one user for the benefit of all. (See also Caching proxy server.) Some search engines, such as Google or Yahoo!, also store cached content from websites.Apart from the facilities built into Web servers that can determine when files have been updated and so need to be re-sent, designers of dynamically-generated Web pages can control the HTTP headers sent back to requesting users, so that transient or sensitive pages are not cached. Internet banking and news sites frequently use this facility.Data requested with an HTTP 'GET' is likely to be cached if other conditions are met; data obtained in response to a 'POST' is assumed to depend on the data that was POSTed and so is not cached.。
第一章 Internet和World Wide Web简介
表示层的主要功能： 表示层的主要功能：
• 用于处理在两个通信系统中交换信息的 表示方式； • 数据格式变换； • 数据加密与解密； • 数据压缩与恢复。
–变换 变换 –加密 加密 –压缩 压缩
应用层的主要功能: 应用层的主要功能:
• 为应用程序提供了网络服务; • 应用层需要识别并保证通信对方的可用 性，使得协同工作的应用程序之间的同 步; • 建立传输错误纠正与保证数据完整性的 控制机制。
– NSFnet
1、Internet的定义
• Internet是指这样一个全球的信息系统：
– 使用IP或者其后续的标准作为唯一全局地址命名而逻辑 连接在一起的； – 能够通过TCP/IP或者兼容的协议进行通信的； – 基于上述定址和通信技术，提供可访问、高质量的相 关私有或者公共的服务的信息系统。
• 2010年1月13日，国务院常务会议决定加快推进电信网、 广播电视网、互联网三网融合，并审议通过了推进三网融 合的总体方案。
– 中国三网融合工作将分两个阶段进行。 – 2010年至2012年为试点阶段，以推进广电和电信业务双向阶段性 进入为重点，制定三网融合试点方案，选择有条件的地区开展试 点，不断扩大试点广度和范围；加快电信网、广播电视网、互联 网升级改造，加快培育市场主体，组建国家级有线电视网络公司， 基本形成保障三网融合规范有序开展的政策体系和体制机制。 – 2013年至2015年为推广阶段，要总结推广试点经验，全面推进三 网融合；自主创新技术研发和产业化取得突破性进展，掌握一批 核心技术，宽带通信网、数字电视网、下一代互联网的网络承载 能力进一步提升。
• Socket是对TCP/IP函数调用的封装。 • 这种封装对基于TCP/IP的编程带来了极大 的方便，因此通过Socket实现网络编程非 常简单。 • Socket告诉程序员在服务器端和客户端应 该按照某些特定的程序框架完成连接和数 据传输。
Three dimensional visualization of the World Wide Web
Three Dimensional Visualization of the World Wide WebSteve Benford, Ian Taylor, David Brailsford, Boriana Koleva, Mike Craven, Mike Fraser, Gail Reynard , Chris GreenhalghUniversity of NottinghamNottingham, UKEmail: sdb@IntroductionAlthough large-scale public hypermedia structures such as the World Wide Web are popularly referred to as "cyberspace", the extent to which they constitute a space in the everyday sense of the word is questionable. This paper reviews recent work in the area of three dimensional (3D) visualization of the Web that has attempted to depict it in the form of a recognizable space; in other words, as a navigable landscape that may be visibly populated by its users. Our review begins by introducing a range of visualizations that address different aspects of using the Web. These include visualizations of Web structure, especially of links, that act as 3D maps; browsing history; searches; evolution of the Web; and the presence and activities of multiple users. We then summarize the different techniques that are employed by these visualizations. We conclude with a discussion of key challenges for the future.Visualizing the structure of the WebVarious visualizations have been developed to show the structure of a region of the Web. These are intended to provide users with 3D maps to guide browsing. Common assumptions behind these visualizations are that 3D interfaces may be capable of displaying a larger volume of information in a single display than 2D, and that users may more easily learn the structure of the Web as a result of flying though a 3D landscape [Benford 1996]. Perhaps the most obvious representation of Web structure is as a graph of nodes connected by links. Natto [Shiozawa 1997] visualizes a number of Web pages by drawing such a node/link graph that is initially distributed on a flat horizontal plane. The placement of the nodes is dictated by attributes of the Web page (e.g. its size, title, number of images) which are mapped to the two-axis of the plane. The user may select nodes and raise them vertically to de-occlude the structure. Adjacent (linked) nodes maintain a close proximity to the raised nodes so that the structure is gradually "disentangled" from the plane. Figure 1 shows a typical result of this process. Natto demonstrates a method of de-occlusion by manual control, however, there are limits to the number of nodes that may comfortably occupy the flat plane before selection becomes difficult. Also, the range of pages is fixed when the visualization is generated.__________________________FINAL DRAFT of paper which appeared in ACM "Computing Surveys" 31(4es), December 1999.Figure 1: A selection of pages in Natto.Narcissus [Hendley 1995] also produces a graph-like representation. Occlusion is automatically reduced through the metaphor of attractive and repulsive forces. Web pages (nodes) exert repulsive forces on each other, whereas the links between them lead to attractive forces. Simulating these forces results in tightly inter-linked sets of pages being grouped into spatial clusters within the visualization. Figure 2 demonstrates a resulting graph.Figure 2: Web site visualisation with clustering in Narcissus.Although occlusion can still occur, the problem of two objects occupying the same space at the same time is eliminated. An additional scaling mechanism is offered by agglomerating clusters into a single, identifiable object. Narcissus does this by surrounding clusters with a translucent surface to effectively remove most of the detail.An alternative approach has been demonstrated by Munzner and Burchard [Munzner 1995] in the construction of three-dimensional hyperbolic space that supports "focus + context" exploration of hypertext structure. The hyperbolic space is formed inside a sphere whose surface is conceptually an infinite distance from the centre. Nodes close to the centre of the sphere appear large and it is here that the focus is achieved. Figure 3 provides an example of this layout for several WWW pages.This work is similar to that of Lamping et al. Lamping 1995] but adds a third dimension with the intention of allowing a higher information density within the space.Figure 3: Hyperbolic layout of a number of pages.In the HotSauce [HotSauce 1999] Web browser from Apple Computers the links are implicit. The HotSauce browser represents Web pages as floating text labels in a 3D space. Pages at the higher level of the hierarchy in a Web server appear large in the foreground whilst the next level would be further away, distributed evenly in the background of their parent page label. The user can "walk" through the labels, progressively bringing lower levels into the foreground. Labels can be repositioned or selected to invoke the content. Figure 4 contains an initial HotSauce view of the Apple Computer Web site.The Perspecta SmartContent [SmartContent 1999] viewer adopts a similar approach to HotSauce with the addition of link representation. It also allows the user to move the viewpoint into the page hierarchy to reveal detail at lower levels.Figure 4: Pages as viewed in the HotSauce BrowserTwo further visualizations of Web structure move away from a graph like representation.The Open Text Web Index visualization [Bray 1996] visualizes several variables associated with Web sites. Parameters such as number of pages, number of links to and from these pages, and domain identifiers, define a composite object that is placed in a 3D space. Such objects combine distinct visual components to represent information around a single unit, i.e. the Web site. The distance between them is determined by the degree of connectivity between the two sites. A view of these sites is shown in figure 5. The lack of detail in the visualization prohibits its use as a page browser but acts as a map at the site level.Figure 5: A view of the web generated from the Open Text Web index.MAPA [Durand 1998] is a visualization that aims to improve navigation in large Web sites of between 500 and 50,000 pages. MAPA presents pages as square icons that stand in rows and columns on a flat plane. A focus page is placed at the front edge of the plane and its child pages form a row behind the focus page. Each child page then has its children behind it so as to form a single column behind the page. Essentially, this aims to provide a layout mechanism with minimal visual clutter. Figure 6 demonstrates this layout with a view of the pages within a company Web site.Figure 6: A Web site viewed in MAPA.Visualizing browsing historyAlthough they share many common techniques with the systems described above, visualizations of browsing history provide images of where the user has been as opposed to maps of where they might go.WebPath [FrÈcon 1998] generates a three-dimensional representation of a Web browsing history within the DIVE distributed virtual reality environment. WebPath runs alongside a conventional browser and is updated whenever a page is visited. Each page is represented as a cube upon which one of three page properties is displayed (the page background image, the first image in-lined in the HTML or the page background colour). The vertical position of the cube is incremented at each visit so as that the most recently visited cube is at the highest point. Semi-transparent layers divide the space so that the older pages gradually become more obscure due to a fogging effect. This effect can be seen over a number of successive layers in figure 7.Figure 7: Browsing history as depicted by WebPath.The horizontal position of the cube can be determined dynamically during run-time, either by mapping the horizontal axes to two of a possible eight metrics (e.g. loading time, number of images, sever name) or geographically over a world map. Also, successive pages are linked by directed arcs. All visited pages result in a new cube, irrespective of whether they have been previously visited. WebPath also extends a web history by allowing dynamic querying using three variables. However, the tool acts as a reminder to already viewed pages rather than as a guide to undiscovered regions of the Web.The WebForager and the WebBook [Card 1996] are two related designs that were born out of the observation that the Web does not provide a particularly sophisticated information workspace. In particular, current Web browsers provide only limited support for personalisation through the use of bookmarks, and even these become difficult to work with when composed of many entries. Also, the use of a window for a single Web page inhibits smooth interaction with multiple pages. Their method of enhancement is to gather related pages using a book metaphor (the WebBook) and to place both books and pages in a dynamic workspace termed the Web Forager as seen in figure 8. The Web Forager was designed to scale the space for, and provide rapid interaction with, many pages. In addition to the page and book metaphor, a "bookcase" is provided to allow a further level of aggregation. Although the workspace enhances interaction with a number of Web pages, there is no visual representation of Web structure and meta-data.Figure 8: A WebBook in the foreground of the Web Forager. (Image copyright © 1996 Association for ComputingMachinery)WWW3D incrementally constructs a 3D map of the user's current browsing session so that they see each new Web page within the context of those that have already been visited [Snowdon 1997]. It adopts the graph-like approach where each page is represented as a sphere with hyperlinks being represented by arrows between the spheres. An incremental version of Fruchterman and Reingold's Force Directed Placement (FDP) algorithm [Fruchterman 1991] (a force simulation algorithm) is used to dynamically regenerate the layout of this map so as to take account each new page and any additional cross links that are encountered. Figure 9 shows an example of a browsing session in WWW3D.Figure 9: A browsing history in WWW3D.As a further note, the LEADS system [Ingram 1996], is a meta-visualization tool to enhance the legibility of information visualisations - i.e., the ease with which users may learn to navigate their structure during a repeated series of visits. Based on Kevin Lynch's observations on the legibility of physical cityscapes, LEADS automatically enhances visualizations with legibility features such as distinct districts, landmarks, edges, nodes and paths. One demonstration of LEADS involved enhancing the output of WWW3D in order to make the browsing history more legible.WWW3D suffers from several limitations. Scalability is limited due to the demands of the FDP algorithm; the layouts produced are difficult to read, especially where there is complex inter-linking between pages; and it only shows a history of where the user had been, with no indication of where they might go. The HyperVIS system is a successor to WWW3D that attempts to address these problems and that also combines mapping and visualisingbrowsing history [Brown 1996]. HyperVIS displays a browsing history as a 3D graph, but also continually maps out a region of the Web in advance of the user's current position. The extent of this forward mapping can be limited by a user-specified scope that combines a maximum search depth, maximum number of pages to be considered and various filters that can be applied against URLs. These filters include the ability to limit the mapping to the contents of specific servers or even directories within servers. To aid scalability, the visualization is based upon a hierarchy of regions. Each region can be folded or unfolded according to the user's level of interest or proximity. Each region can also use a locally defined visualization algorithm to present its contents, supporting visualisation styles beyond 3D graphs such as cone-trees. A further aid to scalability is a link aggregation algorithm that shows many individual links between two clusters as a single arrow of an appropriate thickness.Visualizing the evolution of the WebIn contrast to the previous visualizations of a single user's browsing history, the Time Tube [Chi 1998] visualises the evolution of a Web site over a period of time. Various attributes of the site such as frequency of access, paths taken by browsers, and the age of its information are mapped to a disk tree visualization. This is formed by drawing the tree structure of the site as a disk shape in which the centre is the root page and hyperlink trees branch out around the root. A number of disks are presented in parallel along a time axis forming a time tube, thus demonstrating the evolution of the Web site over time. Figure 10 shows a tube formed by four disk trees resulting from weekly sampling over a period of one month. The user can interactively extract slices from the tube and rotate the tube. They can zoom into each slice to reveal greater detail. A conventional Web browser can also be invoked to view specific pages of interest. The Time Tube is of particular use when temporal qualities of hypertext structures are to be revealed and analysed.Figure 10: A Time Tube formed by the evolution of a Web site in four weekly increments.Visualizing Web searchesWhen searching the Web, the user typically enters one or more keywords and in return is presented with a list of matching pages, rank ordered according to how well they match. It may be difficult for the user to compare the results returned by different queries in order to home in on pages that match successive or multiple combinations of keywords. VR-VIBE is a 3D interactive visualization that enables users to dynamically compare the results of multiple search queries [Benford 1997]. VR-VIBE is based on an earlier 2-D system by Olsen et al. called VIBE [Olsen 1993] and works as follows:•the user enters a number of queries, each consisting of several keywords.•each query is assigned a position in 3D space, either directly by the user by dragging it or automatically by the system.•VR-VIBE matches each page in its local catalogue against each query, resulting in a score that represents the relative attraction of that page to that query. From this, the overall relevance of a specific page to all of the queries can be calculated (the sum of all scores for this page), as can the overall significance of eachquery (the sum of all scores across for this query).A 3D representation of the search space is constructed as follows. An icon representing each matched page is located at its relative centre of attraction to all of the currently active queries. Thus, a page which is attracted to only one query will be located next to that query, whereas a page which is attracted to several queries will be located somewhere between them, with its exact position depending on the relative strengths of the attractions. It is as if the queries exert a gravitational pull on the pages. The overall relevance of each page is mapped onto the size and shade of its icon; the bigger and brighter it is, the greater the overall relevance to all of the queries. Similarly, the overall significance of each query is mapped onto its brightness; thus, the brighter it is the greater its "pull" on the pages in the space. The resulting 3D visualisation gives the user a sense of which pages are generally interesting (big and bright ones) and also which pages are most relevant to which specific keywords (spatial position).Figure 11: Visual searching with VR-VIBE.An important aspect of VR-VIBE is the way in which users can dynamically manipulate the visualisation. They may fly through the 3D scene in order to home in on specific areas or zoom out for an overview. They may select pages in order to retrieve their contents. They may select queries in order to activate or de-activate them. They may dynamically add new queries. They may reposition queries by dragging them or asking the system to "tidy" them into a sensible configuration. Finally, they may use a relevance filter widget to cull all pages whose overall relevance falls below a set threshold. Figure 11 shows a screen shot from VR-VIBE. Five queries (octahedra) are arranged as a pyramid and 1500 documents (blocks) are stretched between them. The relevance filter (vertical bar with slider) can be seen towards the bottom left as can representations of several other users (see following section). Visualizing the users of the WebAlthough a hypertext may be shared by many users who are simultaneously accessing its pages and links via a common server, hypertext implementations tend to treat users as something that are outside of the system. An alternative approach is to consider users to be an integral part of the hypertext and to make their presence and actions visible to one another, as they would be if they were browsing books in a library or posters in front of a notice board. Several 3D Web visualisations have included representations of users, either so that they may worktogether, for example collaboratively browsing and searching, or so that the hypertext becomes a meeting place where encounters between people with similar interests can occur.One approach is to create the visualizations using the technology of collaborative virtual environments, distributed multi-user virtual reality systems that support co-operation [Benford 1995]. In this case, several users may share the same visualization, for example a 3D map. Each user independently controls their own viewpoint and is represented to others through a graphical embodiment called an avatar that indicates who they are and what they are looking at within the visualization. Users may also communicate with one another using a combination of text chat, real-time audio, video views that are embedded within the visualization (e.g., as faces on avatars) and avatar gestures. Several of the visualizations described above support this kind of multi-user access including WWW3D, VR-VIBE, WebPath and HyperVIZ. Figure 12 shows an image from the WWW3D system in which several users can be seen clustered around different nodes in a 3D Web map.Figure 12: representing 2-D users in WWW3D.The Information Garden [Crossley 1997] is a shared visualization of information provided by the Jasper Internet indexing tool. The 3D visualization is pre-prepared (as opposed to being dynamically created) and is based around a circular structure that is divided into two main areas. The centre contains a forum in which users can meet and communicate using various media including text, audio and video. Surrounding this area are information structures or "plants" that visually represent document clusters. Each plant is formed by a central stalk, from which documents radiate as stalks. Each stalk has a color coded square on its end to represent the status of the document (e.g., dead link, updated since visited). Users can bring their own information into the shared space or take "cuttings" from the plants to develop personal copies.Figure 13: The Information Garden.One distinction between these various approaches is whether the users are located in a shared Cartesian space (i.e., they see the same 3D visualization, albeit from different perspectives) or whether they each see their own subjective visualization with the relative positions of other users being indicated by avatars. WWW3D, VR-VIBE, WebPath and the Information Garden adopt the former approach. HyperVIZ adopts the later, showing other users' avatars as facing the page on which they are currently focusing.Once again, scalability is a problem, this time in coping with a large number of simultaneous users. One potential solution has been demonstrated by an extension to WWW3D in which a Web page or small group of Web pages can be treated as a sub-region. Users can communicate with others in their current region (page or site) and may be visually aware of the presence of other users in enclosing or nearby regions [Snowdon 1997].Our final example of visualising the users of a hypertext involves creating persistent and open connections between information on the Web and the physical world. In the Internet Foyer [Benford 1995], a 3D visualisation of an organisation's home pages, complete with their current visitors, is projected into its physical reception area. At the same time, visitors to the visualisation arriving over the network see a live video view looking out into the reception area. Given an open audio link between the virtual and physical spaces, visitors to the home pages are able to communicate with those in the reception area, creating an single entry point into the organisation's physical and electronic spaces.SummaryWe have surveyed different approaches to creating 3D visualizations of the World Wide Web. These have spanned visualizations of the structure of the Web, the history of browsing sessions, searches, the evolution of the Web, and the presence of other users on the Web. Between them these visualizations have introduced a range of visualization styles and techniques to manage scalability, interaction and information sharing.At present, most of the work in this area is focusing on demonstrating new approaches and techniques and there is little widespread experience with them or evidence for their effectiveness. Trials and evaluation are very much a priority for future work. However, what is clear is that these approaches share a common vision - the idea of transforming the from being a structure that is experienced on page at a time through a 2D browser to being a structured space that may be navigated and potentially populated by many users.AcknowledgementsWe would like to acknowledge the owners for their permission to reproduce the images contained in this paper.References[Benford 1995] Steven D. Benford, David Snowdon, Chris M. Greenhalgh, Rob J. Ingram, and Ian Knox."VR≠VIBE: A Virtual Environment for Co≠operative Information Retrieval" in Computer Graphics Forum, 14(3), NCC Blackwell, [16], 1995.[Benford 1996] Steven D. Benford, Chris C. Brown, Gail T. Reynard, and Chris M. Greenhalgh. "Shared Spaces: Transportation, Artificiality and Spatiality" in Proceedings of ACM CSCW '96, Boston, MA 77-86, [18], 1996.[Benford 1997] Steven D. Benford, David N. Snowden, Chris C. Brown, Gail T. Reynard, and Rob J. Ingram. "Visualising and Populating the Web: Collaborative Virtual Environments for Browsing, Searching and Inhabiting Webspace" in Computer Networks and ISDN Systems, 29, pp. 1751≠1761, Elsevier, 1997. First appeared in Proc. JENC'8 (8th Joint European Networking Conference), Edinburgh, UK, May 12-15th, 1997.[Bray 1996] Tim Bray. "Measuring the Web" in Proceedings of Fifth International World Wide Web conference, Paris, France, 993-1005, May 1996.[Brown 1996] Chris C. Brown and Steven D. Benford. "Tracking WWW Users: Experience from the Design of HyperVIS" in Proceedings of WebNetπ96: World Conference of the Web Society, 57≠62, San Francisco, CA, Association for the Advancement of Computing in Education, [14], October 1996.[Card 1996] Stuart K. Card, George G. Robertson, and William York. "The WebBook and the Web Forager: An Information Workspace for the World-Wide Web" in Proceedings of ACM SIGCHI '96, Vancouver, Canada,111≠117, April 1996.[Chi 1998] Ed H. Chi, James Pitkow, Jock D. Mackinlay, Peter Pirolli, Rich Gossweiler, and Stuart K. Card. "Visualizing the Evolution of Web Ecologies" in Proceedings of ACM SIGCHI '98, Los Angeles, CA, 400≠407, April 1998.[Crossley 1997] Martin Crossley, John Davies, Rob Taylor-Hendry and Andy McGrath. "3D Internet Developments" in BT Technology Journal, 15(2), 179, April 1997.[Durand 1998] David G. Durand and Paul Kahn. "MAPA: A System for Inducing and Visualizing Hierarchy in Websites" in Proceedings of ACM Hypertext '98, Pittsburgh, PA, 66-78, June 1998.[FrÈcon 1998] Emmanuel FrÈcon and Gareth Smith. "WebPath ≠ A Three≠Dimensional Web History" Proceedings of IEEE Symposium on Information Visualization (InfoVis å98), Chapel Hill. NC, 3-10, [9] , 1998. [Fruchterman 1991] Thomas M. J. Fruchterman and Edward M. Reingold. "Graph Drawing by Force Directed Placement" in Software Practice and Experience, 21(11), 1129-1164, November 1991.[Hendley 1995] Robert J. Hendley, Nicholas S. Drew, Andrew Wood, and Russell Beale. "Narcissus: Visualizing Information" in Proceedings of the 1995 Information Visualization Symposium, Atlanta, GA, 90-96, 1995. [HotSauce 1999] /hotsauce, [5], 1999.[Ingram 1996] Rob J. Ingram and Steven D. Benford. "The Application of Legibility Techniques to Enhance 3D Information Visualisations" in The Computer Journal, 39 (10), 819≠836, 1996.[Lamping 1995] John Lamping, Ramona Rao, and Peter Pirolli. "A Focus+Context Technique Based on Hyperbolic Geometry for Visualizing Large Hierarchies" in Proceedings of ACM SIGCHI '95, Denver, CO, 401≠408, May 1995.[Munzner 1995] Tamara Munzner and Paul Burchard. "Visualizing the Structure of the World Wide Web in 3D Hyperbolic Space" in Proceedings of VRML '95, San Diego, CA, 33-38, December 1995.[Olsen 1993] Kai A. Olsen, Robert R. Korfhage, Kenneth M. Sochats, Michael B. Spring, James G. Williams. "Visualisation of a Document Collection: The VIBE System, Information Processing and Management, 29 (1),69≠81, 1993.[Shiozawa 1997] Hidekazu Shiozawa and Yutaka Matsushita. "WWW visualization giving meanings to interactive manipulations" in Advances in Human Factors/Ergonomics 21B (HCI International π97), San Francisco, CA, 791-794, August 1997.[SmartContent 1999] , [6], 1999.[Snowdon 1997] David Snowdon, Steven D. Benford, Chris M. Greenhalgh, Rob Ingram, Chris C. Brown, Lennart FahlÈn and MÂrten Stenius. "A 3D Collaborative Virtual Environment for Web Browsing" in Virtual Reality Universe '97, Santa Clara, California, USA, [11], April 1997.。
万维网
WWW：WWW是环球信息网（World Wide Web）的缩写也可以简称为Web，中文名称为“万维网”。
另外，www也是世界气象监视网的英文简称。
(一)产品及服务万维网（亦作“网络”、“WWW”、“3W”，英文“Web”或“World Wide Web”），是一个资料空间。
在这个空间中：一样有用的事物，称为一样“资源”；并且由一个全域“统一资源标识符”（URL）标识。
这些资源通过超文本传输协议(Hypertext Transfer Protocol）传送给使用者，而后者通过点击链接来获得资源。
从另一个观点来看，万维网是一个透过网络存取的互连超文件(interlinked hypertext document）系统。
万维网联盟（World Wide Web Consortium，简称W3C），又称W3C理事会。
1994年10月在拥有“世界理工大学之最”称号的麻省理工学院(MIT）计算机科学实验室成立。
建立者是万维网的发明者蒂姆·伯纳斯·李。
万维网常被当成因特网的同义词，但万维网与因特网有着本质的差别。
因特网（Internet）指的是一个硬件的网络，全球的所有电脑通过网络连接后便形成了因特网。
而万维网更倾向于一种浏览网页的功能。
(二)发展简史最早的网络构想可以追溯到遥远的1980年蒂姆·伯纳斯·李构建的ENQUIRE项目。
这是一个类似维基百科的超文本在线编辑数据库。
尽管这与我们现在使用的万维网大不相同，但是它们有许多相同的核心思想，甚至还包括一些伯纳斯·李的万维网之后的下一个项目语义网中的构想。
1989年3月，伯纳斯－李撰写了《关于信息化管理的建议》一文，文中提及ENQUIRE 并且描述了一个更加精巧的管理模型。
1990年11月12日他和罗伯特·卡里奥（Robert Cailliau）合作提出了一个更加正式的关于万维网的建议。
在1990年11月13日他在一台NeXT工作站上写了第一个网页以实现他文中的想法。
万维网带来的好处英语作文
万维网带来的好处英语作文The World Wide Web, a vast digital library, has revolutionized the way we access information. It's like having the entirety of human knowledge at our fingertips, making learning more accessible than ever before.With the click of a mouse, we can connect with people across the globe, fostering a sense of global community. This interconnectedness has broken down geographical barriers, allowing for collaboration and friendship that transcends borders.The internet has also transformed commerce, making it possible to shop from the comfort of our homes. This convenience has not only saved time but has also opened up a marketplace that is virtually limitless, offering a wide array of products and services.Moreover, the web has become a platform for self-expression, where individuals can share their thoughts, art, and ideas. This democratization of media has given a voice to the voiceless and has empowered people to participate in the global conversation.Lastly, the educational potential of the web is immense. Online courses and resources cater to every learning style and subject, allowing for personalized education that can be tailored to individual needs. This adaptability is atestament to the web's ability to adapt and evolve with the ever-changing landscape of knowledge.。
The diameter of the world wide web
a r X i v :c o n d -m a t /9907038v 2 [c o n d -m a t .d i s -n n ] 10 S e p 1999The diameter of the world wide webDespite its increasing role in communication,the world wide web (www)remains the least controlled medium:any individual or institution can create websites with unrestricted number of documents and links.This unregulated growth leads to a huge and complex web,which is a large directed graph,whose vertices are documents and edges are the links (URLs)pointing from one document to another.The topology of this graph determines the web’s connectivity and,consequently,our effectiveness in locating information on the www.However,due to its large size (estimated to be at least 8×108documents [1]),and the continuously changing documents and links,it is impossible to catalogue all vertices and edges.The challenge in obtaining a complete topological map of the www is illustrated by the limitations of the commercial search engines:Northern Light,the search engine with the largest coverage,is estimated to index only 38%of the web [1].While great efforts are made to map and characterize the Internet’s infrastructure [2],little is known about what truly matters in searching for information,i.e.,about the topology of the www.Here we take a first step to fill this gap:we use local connectivity measurements to construct a topological model of the www,allowing us to explore and characterize the large scale properties of the web.To determine the local connectivity of the www,we constructed a robot,that adds to its database all URLs found on a document and recursively follows these to retrieve the related documents and URLs.From the collected data we determined the probability P out (k )(P in (k ))that a document has k outgoing (incoming)links.As Figs.1a and b illustrate,wefind that both P out (k )and P in (k )follow a power-law over several orders of magnitude,remarkably different not only from the Poisson distribution predicted by the classical theory of random graphs by Erd˝o s and R´e nyi [3,4],but also from the bounded distribution found in recent models of random networks [5].The power law tail indicates that the probability of finding documents with a large number of links is rather significant,the network connectivitybeing dominated by highly connected web pages.The same is true for the incoming links:the probability offinding very popular addresses,to which a large number of other documents point,is non-negligible,an indication of theflocking sociology of the www.Furthermore, while the owner of each web page has complete freedom in choosing the number of links on a document and the addresses to which they point,the overall system obeys scaling laws characteristic only of highly interactive self-organized systems and critical phenomena[6].To investigate the connectivity and the large-scale topological properties of the www, we construct a directed random graph consisting of N vertices,assigning to each vertex k outgoing(incoming)links,such that k is drawn from the power-law distribution shown in Fig.1a and b.To achieve this,we randomly select a vertex i and increase its outgoing(in-coming)connectivity to k i+1if the total number of vertices with k i+1outgoing(incoming) links is less than NP out(k i+1)(NP in(k i+1)).A particularly important quantity in a search process is the shortest path between two documents,dl,defined as the smallest number of URL links one needs to follow to navigate from one document to the other.As Fig.1c shows,wefind that the average of d over all pairs of vertices follows d =0.35+2.06log(N), indicating that the web forms a small-world network[5,7],known to characterize social or biological ing N=8×108[1],wefind d www =18.59,i.e.,two randomly chosen documents on the web are on average19clicks away from each other.Since for a given N,d follows a Gaussian distribution, d can be interpreted as the diameter of the web,a measure of the shortest distance between any two points in the system.Despite its huge size,our results indicate that the www is a highly connected graph of average diameter of only19links.The logarithmic dependence of d on N is important to the future potential of the www:wefind that the expected1000%increase in the size of the web over the next few years will change d from19to only21.The relatively small value of d suggests that an intelligent agent,i.e.,who can interpret the links and follow only the relevant one,can find in a short time the desired information by navigating the www.However,this is not the case for a robot,that locates the information based on matching strings:wefind that such a robot,aiming to identify a document at distance d ,needs to search M( d )≃0.53N0.92documents which,using N=8×108[1],leads to M=8×107,i.e.,to10%of the full www. This indicates that robots cannot benefit from the highly connected nature of the web,their only successful strategy being indexing as large a fraction of the www as possible.The uncovered scale free nature of the link distributions indicates that collective phe-nomena play an unsuspected role in the development of the www[8],requiring us to look beyond the traditional random graph models[3–5,7].A better understanding of the web topology,aided by modeling efforts,is crucial in developing search algorithms or designing strategies for making information widely accessible on the www.The good news is that,due to the surprisingly small diameter of the web,all that information is just a few clicks away.R´e ka Albert,Hawoong Jeong and Albert-L´a szl´o Barab´a siDepartment of Physics,University of Notre-Dame,Notre Dame,Indiana46556,USAemail:alb@REFERENCES[1]Lawrence,S.and Giles,C.L.,Nature400,107-109(1999).[2]Claffy,K.,Monk,T. E.and McRobb, D.,Nature Web Matters,Jan.7(1999);/webmatters/tomog.html[3]Erd˝o s,P.and R´e nyi,A.,Publ.Math.Inst.Hung.Acad.Sci5,17-61(1960).[4]Bollob´a s,B.,Random Graphs(Academic Press,London,1985).[5]Watts,D.J.and Strogatz,S.H.,Nature393,440-442(1998).[6]Bunde,A.and Havlin,S.,Fractals in Science(Springer-Verlag,1994).[7]Barth´e l´e my,M.and Amaral,L.A.N.,Phys.Rev.Lett.82,3180-3183(1999).[8]Barab´a si,A.-L.,Albert,R.and Jeong,H.,/abs/cond-mat/990768FIGURES1010101010410-810-610-410-2100P o u t (k)1010101010410101010106N357911<d >10010210-810-610-410-2k+1k+1P(k)(c)k+1P o u t (k )FIG.1.The distribution of (a)outgoing links (URLs found on an HTML document)and (b)incoming links (URLs pointing to a certain HTML document).The data were obtained from the complete map of the domain,that contains 325,729documents and 1,469,680links.The dotted lines in (a)and (b)represent the analytical fits we used as input distributions in constructing the topological model of the www,the tail of the distributions following P (k )∼k −γ,with γout =2.45and γin =2.1.(c)Average of the shortest path between two documents as a function of the system size,as predicted by the model.As a check of the validity of our predictions,we have determined d for documents in the domain .The measured d =11.2agrees well with the prediction d 3×105 =11.6obtained from our model.To show that the power-law tail of P (k )is a universal feature of the www,in the inset we show P out (k )obtained by starting from (squares), (upward triangles)and snu.ac.kr (downward triangles).The slope of the dashed line is γout =2.45,as obtained from in (a).。
中考英语模拟题五 试题
课标版英语中考模拟题〔五〕一、听力测试〔25分〕A〕听下面10段对话，每段对话后有一小题。
听完每段对话后，你都10秒钟的时间是答复有关小题和阅读下一小题。
每段对话读两遍。
〔每一小题1分〕( ) 1. When did the match begin?A．At 9:50 B．At 10:00 C．At 10:10( ) 2. Were is the man probably going this afternoon?A．To a museum B．To a book shop C．To a hospital( ) 3. What’s the weather like today?A．Fine B．Cloudy C．Rainy( ) 4. How much will the man pay for the socks?A．Three dollars B．Four dollars C．Eight dollars( ) 5. Where a re the speakers now?A．In a shop B．On the bus C．At home( ) 6. How soon will Mr. Green come?A．In five minutes B．In five hours C．In five days( ) 7. Who mended the bike?A．Susan B．Susan’s father C．Susan’s friend( ) 8. What does the woman mean?A．She wouldn’t like to go B．She has a better ideaC．She will go if it’s fine( ) 9. Why is the woman moving?A．The new house is more beautiful B．She needs a quiet placeC．She wants to listen to songs( ) 10. What does Kate think of English?A．It’s not so difficult as other subjectsB．It’s interesting but difficult C．It’s interesting and easyB)听下面两段对话和一段独白，听完第一段对话后答复第11至第13小题；听完第二段对话答复第14至第16小题；听完独白后答复第17至第20小题。
万维话题作文英语
万维话题作文英语在这个信息爆炸的时代，网络已经成为我们获取知识、交流思想的重要渠道。
而在网络上，万维网（World Wide Web）被誉为信息的海洋，无数的话题在其中交织，引发了人们对各种问题的思考和讨论。
今天我们就来谈谈以万维话题为题材的英语作文。
Title: The Impact of the World Wide Web on Modern Society。
Introduction:The World Wide Web, commonly known as the internet, has become an indispensable part of modern society. It has transformed the way we communicate, gather information, and conduct business. With the vast array of topics available on the web, it serves as a platform for people to exchange ideas, debate issues, and explore diverse perspectives.Body:1. Access to Information:The internet has democratized access to information, making knowledge more accessible than ever before. Through search engines and online databases, individuals canquickly find information on virtually any topic imaginable. This easy access to information has empowered individuals to educate themselves on a wide range of subjects, from academic research to DIY projects.2. Communication and Connection:The World Wide Web has revolutionized communication, breaking down geographical barriers and enabling instant communication across the globe. Social media platforms, email, and messaging apps allow people to connect with friends, family, and colleagues regardless of distance. This interconnectedness has fostered global communities and facilitated the exchange of ideas on a scale never seen before.3. Diversity of Topics:One of the most remarkable aspects of the internet is the sheer diversity of topics it encompasses. From news and current events to niche hobbies and interests, there is something for everyone on the web. This vast array of topics encourages exploration and curiosity, exposing individuals to new ideas and perspectives they may not encounter in their everyday lives.4. Impact on Society:The World Wide Web has had a profound impact on society, shaping how we learn, work, and interact with one another. It has transformed industries such as media, entertainment, and commerce, creating new opportunities and challenges. However, it has also raised concerns about privacy, misinformation, and the digital divide, highlighting the need for ethical guidelines and regulations to govern its use.Conclusion:In conclusion, the World Wide Web has become an integral part of modern society, influencing virtuallyevery aspect of our lives. Its vast array of topics and accessibility have revolutionized how we access information, communicate with others, and engage with the world around us. While it has brought about tremendous benefits, it also poses challenges that must be addressed to ensure a safe, equitable, and inclusive online environment for all.This essay explores the impact of the World Wide Web on modern society, touching upon its influence on information access, communication, diversity of topics, and societal implications. It underscores the transformative power ofthe internet while acknowledging the need for responsible use and regulation to address its challenges.。
2024初中英语中考阅读理解高频考点必刷专项练习卷 (4668)
一、阅读理解文章大意：本文介绍了清明节的由来，以及人们在清明节这天会做什么。
1. A well-known poem by Tang dynasty poet Du Mu describes a sad scene (场景) in early April, “Rains fall heavily as Qingming comes, andpassersby with lowered spirits go.” This scene takes place on Tomb Sweeping Day, also known as Qingming Festival. 1 It began in the Zhou Dynasty, over 2500 years ago. Chinese people celebrate it to remember and honor their ancestors. This year, Qingming Festival falls on April 5. Tomb Sweeping Day became a public holiday in the Chinese mainland in 2008. 23 . They put the flowers and food in front of the graves. Some may burn joss paper, as money for the dead. After that, they sweep thetombs and cherish (怀念) the memories of their dead family members.Tomb Sweeping Day gives us a chance to show respect to our ancestors. 4 Tomb Sweeping Day is the beginning of the time for outdoor activities in China. 5A．People like Tomb Sweeping Day.B．People have one day off for that day.’C．On this day, families have a big meal at home.D．Tomb Sweeping Day is a traditional Chinese festival.E．Families often go out together or fly kites at this time.F．This tradition also shows that family is an important part of Chinese culture.G．On this day, families bring flowers, food and wine to the grave sites (墓地) of their ancestors2. New NamesWhen you get a pet, the first thing you might do is to give it name. The name should be one you’ll remember. It might also describe the pet. For example, if you get a brown puppy, you might call her Honey.When a new product is invented, people need to give it a name, too. 1 Sometimes people make up new words for a new invention.Sometimes they use older words and combine them in new ways.Lots of electronic products are invented every year, so new computer words are invented all the time. 2 The word Internet was invented in the 1980s to describe the system that links computer networks around the world. Originally, it was called the internetwork.The World Wide Web (the Web) is a huge collection of documents that you can access (存取) through the Internet. 3 Browser (浏览器) isa good name for this software application because you use it to browse, or look around, on the Web.Two words were invented to describe Internet journals: blog and vlog. Blog is a form of web log. 4 Blogs contain words and sometimes pictures, while vlogs contain videos.Another new computer word is e-mail, which is a shortened form of electronic mail. Y ou get your e-mail in a mailbox. 5 Before e-mail, mailboxes were simply boxes where people put paper letters inside to be delivered by letter carriers.The next time you see a new invention, look carefully at its name. Do you see any words or words parts you know? By looking for familiar words, you can often guess what an invention does.A．The Internet is an example.B．Vlog is a shortened form of video log.C．The name helps others remember it – and buy it.D．You use a Web browser to find texts and images.E．You can write an e-mail to the magazine.F．While mailbox isn’t a new word, it’s a new use of an older word.G．Dingding is the name of my cat.文章大意：本文是一篇说明文，主要介绍了印刷机的发展以及贡献。
江苏省泰兴市西城中学八年级英语 练习85(无答案) 人教新目标版
江苏省泰兴市西城中学八年级英语练习85（无答案）人教新目标版听力部分（15分）一、回答问题( )1. A. two time a day B. this time yesterday C. three times a day. ( )2. A. My father likes coffee B. Neither, thanks C. Coffee is better than milk.( )3. A. It’s sunny. B. it’ll be rainy C. it rained yesterday.( )4. A. Buy souvenirs B. Take photos. C. A and B.( )5. A. When the light is green B. When the light is red C. When the light is yellow.二、对话理解( )1 A. Eleven B. Thirty-one C. Twenty( )2 A .Leaning Tower of Pisa. B. The Great Wall C. Statue of Liberty ( )3 A. Lucy B. Bob C. Lily.( )4 A. 2 B. 5 C. 7( )5 A. drink some water B. have a rest C. take some medicine三、短文理解( )1Why did Mrs. White go shopping?A.Because she wanted to buy somethingB.Because she wanted to sit next to the old woman.C.Because she wanted to take away the old woman’s money.( )2Who had a handbag?A. Mrs. WhiteB. The old womanC. Both Mrs. White and the old woman( )3When was Mrs. White sure that her money had been taken away?D.When she found the woman was sitting next to her.E.As soon as she saw the money in the old woman’s handbag.F.When she found her own bag was empty.( )4 Why did Mrs. White take the money from the old woman’s bag herself?G.Because on one was watching her.H.Because she didn’t want to call the police.I.Because she needed money to buy a hat.( )5Which of the following is true?J.The old woman had taken away the money.K.Mrs. White didn’t take her money with her.L.Mrs. White had taken back her money.笔试部分I.词汇（18分）A. 根据句意和所给中文写出句中所缺的单词。
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E-task 2
• Look up two car manufactures’ website ( and ). Configure the car of your choice and report your findings. Make sure to include payment options, shipping options, shipping charges, financing (if any), and delivery schedule.
THE WORLD WIDE WEB
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chapter
©2003 Thomson Learning/South-Western
Slide 1 of 30
Learning Objectives
1. The rising tide of the Internet.
2
2. The makeup of the Web. 3. To understand how the Internet can add value to a business.
©2003 Thomson Learning/South-Western
A brief introduction to Internet
• 互联网（Internet），又称网际网路，或音译 因特网、英特网，是网络与网络之间所串连成 的庞大网络，这些网络以一组通用的协议相连 ，形成逻辑上的单一巨大国际网络。 • 这种将计算机网络互相联接在一起的方法可称 作“网络互联”，在这基础上发展出覆盖全世 界的全球性互联网络称互联网，即是互相连接 一起的网络。
4. Increases connectivity.
5. Makes everything faster, more efficient. 6. Eliminates distance.
©2003 Thomson Learning/South-Western
Slide 11 of 30
Case study: LG Chemical
©2003 Thomson Learning/South-Western
How Can the Internet Add Value to a Business?
Six ways:
1. Enhances value proposition to customers.
2. Reduces operational inefficiencies. 3. Streamlines supply chains.
©2003 Thomson Learning/South-Western
3 Case:
©2003 Thomson Learning/South-Western
3 Case:
• • • • • • •
电子商务应用相关的技术 网络安全技术 搜索技术 数据库技术 传输技术 流媒体技术 ©2003 Thomson Learning/South-Western 其它技术
Brief History …the Internet and Web
For what purpose was the Internet created?
Slide 6 of 30
Brief History …the Internet and Web (continued)
Principles used for designing the Internet include:
No central control. All nodes in the network (e.g., PCs and the terminals of mainframe computers) would be equal in status to all other nodes. Each node has authority to originate, pass, and receive messages.
5. To study the structure of the Web and how sites relate to one another.
6. To learn about the laws that govern the Internet (e.g. Metcalfe’s law).
©2003 Thomson Learning/South-Western
©2003 Thomson Learning/South-Western
• 万维网的核心部分是由三个标准构成的：
1) 统一资源标识符（URL），这是一个世界通用的负 责给万维网上例如网页这样的资源定位的系统。 2) 超文本传送协议（HTTP），它负责规定浏览器和 服务器怎样互相交流。 • 3) 超文本标记语言（HTML），作用是定义超文本文 档的结构和格式。
The primary objective was to create a decentralized network for the U.S. Department of Defense that could withstand nuclear attack.
©2003 Thomson Learning/South-Western
The messages themselves are divided into packets, each with its own address. Each packet begins at some specified source node and ends at some specified destination node. Packets are not wedded to any particular route.
©2003 Thomson Learning/South-Western
Slide 5 of 30
WWW introduction
• 万维网（亦作“Web”、“WWW”、“‘W3’”，英文 全称为“World Wide Web”），是一个由许多互相链 接的超文本hypertext组成的系统，通过互联网 internet访问。 在这个系统中，每个有用的事物，称 为一样“资源”；并且由一个全局“统一资源标识符 ”（URI）标识；这些资源通过超文本传输协议（ Hypertext Transfer Protocol）传送给用户，而后者 通过点击链接来获得资源。1994年10月在麻省理工学 院（MIT）计算机科学实验室成立。
Winner-takes-all market
©2003 Thomson Learning/South-Western
Bowtie Structure
©2003 Thomson Learning/South-Western
Deep web 深层网络
• 迈克尔· 伯格曼将当今互联网上的搜索服务比喻为像在 地球的海洋表面的拉起一个大网的搜索，巨量的表面 信息固然可以通过这种方式被查找得到，可是还有相 当大量的信息由于隐藏在深处而被搜索引擎错失掉。 • 绝大部分这些隐藏的信息是须通过动态请求产生的网 页信息，而标准的搜索引擎却无法对其进行查找。传 统的搜索引擎“看”不到，也获取不了这些存在于暗 网的内容，除非通过特定的搜查这些页面才会动态产 生。于是相对的，暗网就隐藏了起来。据估计，暗网 要比表面网站大几个数量级
chapter
©2003 Thomson Learning/South-Western
Slide 2 of 30
Learning jectives (continued)
4. To understand the myths about the nature of the Internet.
2
chapter
©2003 Thomson Learning/South-Western
1 Case:
©2003 Thomson Learning/South-Western
1 Case:
©2003 Thomson Learning/South-Western
1 Case:
©2003 Thomson Learning/South-Western
Report format
Web site No. 1 No.2 … … … Visit times
Do you observe a winner-take-all structure?
©2003 Thomson Learning/South-Western
©2003 Thomson Learning/South-Western
Slide 7 of 30
Brief History …the Internet and Web (continued)
Principles used for designing the Internet include: (continued)
©2003 Thomson Learning/South-Western
E-task 1
• Conduct a survey of 5 friends. Ask them to recall the name of sites they visited during the past week on any particular day. Prepare a chart with 2 columns（the name and the number of times）. • Meet with your group members. Plot your survey answers.
©2003 Thomson Learning/South-Western
Slide 8 of 30
Structure of the Internet
• Winner-take-all markets