专业英语的复习材料

1、第八单元选择题1. The earliest method of delivering telecommunications is the Telegraph2. With Digital technology ,the electrical impulses only need to correspond to two digits instead of the full range of qualities that compose the original message.3. A(n) Modem is a device that converts between analog and

2、 digital signals,making it possible for a computer to transmit information over a standard telephone line.4. Data communications is the process of transmitting and receiving data in an orderly way so the data that arrives at its destination is an accurate duplication of the data that was sent.5. Bas

3、ic data communications concepts are the building blocks for understanding how data travels on a communications system.第九单元选择题1. These high-speed data services are usually referred to as broadband connections.It is anticipated that they will provide the necessary links between LANs that make what is

4、called the information superhighway a reality2. A public key system allows users to scramble and unscramble their messages easily without a third party intruding.3. The devices on a LAN are known as nodes, and the nodes are connected by cabling through which messages are transmitted. Nodes on a LAN

5、can be wired together in any of three basic topologies, known as bus, ring, and star.阅读理解A local area network (LAN) is a group of computers and other devices dispersed (分散) over a relatively limited area and connected by a communications link that enables any device to interact with any other on the

6、 network. LANs commonly include microcomputers and shared (often expensive) resources such as laser printers and large hard disks. Most (modern) LANs can support a wide variety of computers and other devices. Each device must use the proper physical and data-link protocols for the particular LAN, an

7、d all devices that want to communicate with each other on the LAN must use the same upper-level communications protocol. Although single LANs are geographically limited (to a department or an office building, for example), separate LANs can be connected to form larger networks. Similar LANs are link

8、ed by bridges, which act as transfer points between networks; dissimilar LANs are linked by gateways, which both transfer data and convert it according to the protocols used by the receiving network.The devices on a LAN are known as nodes, and the nodes are connected by cabling through which message

9、s are transmitted. Nodes on a LAN can be wired together in any of three basic topologies, known as bus, ring, and star.对应翻译：局部区域网路（ LAN ） ，是一组计算机和其他设备的分散（分散）的一个相对有限的地区，并连接由通信联系，让任何装置，以进行互动与任何其他对网络。局域网常见的包括微型计算机和共享（通常是昂贵的）的资源，例如激光打印机和大硬盘。大多数（现代）的局域网，可支持多种计算机及其他设备。每一个设备必须使用适当的物理和数据链路协议，为特定网络，以及所有的设备要相

10、互沟通在局域网上必须使用同一高层通信协议。虽然单个局域网相距有限公司（以一个部门或办公楼，举例来说） ，分别局域网可以连通，形成较大的网络。类似局域网的连接桥梁，那些充当传递点之间的网络;异种局域网连接，由网关，这两个公司的数据传输和转换，它根据该议定书所使用的接收网络。 该装置对局域网被称为节点，节点是可以互相布线通过这些讯息传送。节点局域网，可有线一起在任何3个基本拓扑，称为巴士，戒指，和明星 第十单元选择1.URLs are Internet addresses used by Web browsers to locate.网址使用网络浏览器来定位的互联网地址。第11单元选择1. Hum

11、an societies throughout history have had “information specialists”(form traditional healers to newspaper editors);2. Information-processing has become increasingly visible and important in economic , social, and political life.One familiar piece of evidence is the statistical growth of occupations s

12、pecializing in information activities3. The term “Information-processing” covers the generation,storage, transmission, manipulation,and display of information,including numerical,textual,audio,and video data4. Information-processing involves the generation,storage,transmission,manipulation,and displ

13、ay of information.5. According to the text,we can see that an information revolution is now occurring from two interrelated aspects:social and Technological developments.6. The alleged growth of “privatism” (a decline in shared activities as individuals pursue their own interests in isolation)7. Pol

14、arization of the workforce in terms of quality of work and levels of wages has ensued; at the same time a gulf has been opening between employed and unemployed people.8. The pace of adoption of new IT has been very speedy:it is markedly more rapid than that of earlier revolutionary technologies,such

15、 as the steam engine of electric motor9. By the late 1990s the integration of office IT is becoming apparent:material is increasingly exchanged by e-mail(which as finally established itself);10. And communication flows between the senior staff and the shop floor or fieldworkers.11. The “hollow firm”

16、 is one effort to gain flexibility.The company attempts to dispense with the direct ownership and operation of many facilities that would traditionally have belonged to it,instead outsourcing production,distribution,and other tasks to other firms.阅读理解It is frequently claimed that the most potent (强有

17、力的) agent of change on present-day society and the economy will prove to be information technology. The so-called digital revolution whereby informationwhether text, sound, or videocan be converted into, and from, binary digits (bits) and transmitted over global networks is believed to be likely to

18、transform industries such as banking, telecommunications, and publishing. Advances in light-wave communications technology based on optical fibres have vastly increased the volume and speed of information transmission. The development of flat-panel displays (平板显示器) has allowed the computer mobility

19、from the desk. Together these have contributed to the integration of computer and communications technology which, for the user, transcends (超越) space and makes information available on demand.As well as rich opportunities, such a major social change presents severe challenges. One is how to avoid t

20、he creation of a divided society of information “haves” and “have nots”. This is both a national and an international problem. Others relate to ownership and security of information: cyberspace (网络空间) is a new frontier where existing legal principles and practice are having to be rethought. Yet agai

21、n, there are moral issues to be faced about the kinds of information which should be openly available to users of the Internet. 翻译Rapid communication, plus increased access to IT in the home, at work, and in educational establishments, could mean that learning becomes a truly lifelong activityan act

22、ivity in which the pace of technological change forces constant evaluation of the learning process itself.快速的通信，加上在家里、工作场所和教育机构使用信息技术机会的增多，可能意味着学习成为一项真正持续终生的活动在这项活动中，技术变化的速度迫使我们要对学习过程本身不断作出评估。第12单元选择 lectronic commerce may be defined as the entire set of processes that support commercial activities

23、on a(n) network and involve information analysis. E-checks require digital signatures and authentication services to digitall process information between the payer,payee,and bank. Electronic catalogs organize information based on content and allow users to browse through and select the relevant docu

24、ments. These filters could be located at the workstation of the end users or at remote sites. Software agents such as robots,wanderers,and spiders can traverse and locate relevant information. There are two types of smart cards:relationship-based smart cards that allow financial transactions but req

25、uire accounting settlements at the end of each billing cycle,and electronic purses and debit cards that store sums of money and can be used for a variety of services. Electronic is an electronic payment method that emulates the real-life exchange of goods and services for their equivalent currencies

26、. This includes entering credit card information into the system,having it encrypted by the system,and sending the information over the network. Security systems typically consist of a cryptographic system that performs the encryption of plain text data into ciphertext and decryption of ciphertext b

27、ack into plain text data.阅读理解The term electronic commerce encompasses(包含) the entire process of buying, selling, and advertising products and services using electronic communications media. But when people talk about e-commerce today, they're usually referring to the emerging marketplace on the

28、Internet. Retailers of all kinds are now scrambling to establish themselves and reach customers in this new marketplace.The major obstacle to e-commerce is the problem of how to pay for products and services online. How can electronic payments be made convenient, reliable, and secure for consumers a

29、nd retailers alike? As with every other Internet technology, a global standard for online transactions must emerge before e-commerce becomes a widely accepted practice. The drive to establish a standard for electronic money is well underway. Software developers, banks, and credit card companies are

30、all pushing transaction systems to online merchants, each betting that their system will become the standard way to pay for things online. As a Web storefront owner, you must investigate(调查) all the options and offer as many choices to your customers as they demand, while keeping costs and complexit

31、ies from getting out of hand. 翻译Online marketing focuses more on generating publicity and creating a reputation for your Web site rather than on generating sales. Your marketing efforts must be creative, interesting, and constantly changing in order to make your site stand out.在线营销聚焦于引起公众注意，为你的网站创造声

32、誉，而不是提高销售额。你的营销工作必须具有创造性，能够引起人们的兴趣，并且不断变化，以使你的网站卓然出众。第13单元阅读理解 A virus or other unwelcome surprise can lurk in your computer system for days or months without discovery. A time bomb is a computer program that stays in your system undetected until it is triggered by a certain event in time, such as w

33、hen the computer system clock reaches a certain date. A time bomb is usually carried by a virus or Trojan horse. For example, the Michelangelo virus contains a time bomb designed to damage files on your hard disk on March 6, the birthday of artist Michelangelo.A logic bomb is a computer program that is triggered by the appearance or disappearance of specifi