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计算机网络第四版(潘爱民译著)清华大学出版社课后习题答案第1章概述1.答：狗能携带21千兆字节或者168千兆位的数据。
18公里/小时的速度等于0.005公里/秒，走过x公里的时间为x/0.005=200x秒，产生的数据传输速度为168/200xGbps或者840/xMbps。
因此，与通信线路相比较，若x<5.6公里，狗有更高的速度。
2.使用局域网模型可以容易地增加节点。
如果局域网只是一条长的电缆，且不会因个别的失效而崩溃(例如采用镜像服务器)的情况下，使用局域网模型会更便宜。
使用局域网可提供更多的计算能力和更好交互式接口。
3.答：横贯大陆的光纤连接可以有很多千兆位/秒带宽，但是由于光速度传送要越过数千公里，时延将也高。
相反，使用56kbps调制解调器呼叫在同一大楼内的计算机则有低带宽和较低的时延。
4.声音的传输需要相应的固定时间，因此网络时隙数量是很重要的。
传输时间可以用标准偏差方式表示。
实际上，短延迟但是大变化性比更长的延迟和低变化性更糟。
5.答：不，传送.速度为200,000公里/秒或200米/微秒。
信号在10微秒中传送了2千米，每个交换机相当于增加额外的2公里电缆。
如果客户和服务器之间的距离为5000公里，平均通过50个交换机给那些总道路只增加100公里，只是2%。
因此，交换延迟不是这些情形中的主要因素。
6.答：由于请求和应答都必须通过卫星，因此传输总路径长度为160,000千米。
在空气和真空中的光速为300，000公里/秒，因此最佳的第2页，共76页传播延迟为160,000/300，000秒，约533msec。
7.显而易见，在这里没有正确的独立的答案。
但下列问题好像相关：目前的系统有它的很多惯性(检测和平衡)。
当新的团体掌握权力的时候，这惯性可保持法律、经济和社会制度的稳定。
此外，很多人对社会问题没有真的知道事情的真相，但却具有很强烈的、引起争论的意见。
将不允许讲道理的观点写进法律也许不合适。
计算机专业英语教程（第四版）习题答案计算机专业英语教程(第四版)习题答案计算机专业英语（第四版）课后习题答案Unit 1 [Ex 1] Fb5E2RGbCAP [Ex 2] 1. input, storage, processing, and output 2. power; speed; 1. F 2. T 3. T 4. F 5. T 6. T 7. T 8. T 9. T 10.memoryp1EanqFDPw 3. central processing unit memoryDXDiTa9E3d 5. keyboard; [Ex 3] B. A. central processing unit; 1. F 2. D 2. monitor 3. G 4. C 5. B main memory; 6. A 7. E monitorRTCrpUDGiT 8. H5PCzVD7HxA 4. internal; primary;1. user3. data4. keyboard5. data processingjLBHrnAILg6. information [Ex 4] instructions7. computer8. memory 3. manipulates 4.1. input device2. screen, screen 5. retrievexHAQX74J0X 8. Function6. code7. hard copy[Ex. 5] 新处理器开始IT 技术的新时代New Processors Open New Era of IT Technologies Last week, Intel introduced to the public in Russia and other CIS countries a family of processors Intel Xeon E5-2600. They are more powerful and reliable and, importantly, are very economical in terms of energy consumption. Their1 / 30presence opens a new era in the field of IT technologies and means that the cloud technology is getting closer.LDAYtRyKfEThese processors are primarily designed for servers, data centers (DPC) and supercomputers. The emergence of this class of devices is not accidental. According to the regional director of Intel in Russia and other CIS states Dmitri Konash who spoke at the event, the market of IT-technology is developing so rapidly that, according to forecasts, by 2015 there will be 15 billion devices connected to the Internet, and over 3 billion of active users.Zzz6ZB2Ltk 上周，英特尔公司向俄罗斯和其它独联体国家的公众推出了英特尔Xeon E5-2600 系列处理器，它们更加强大可靠，尤其是在能量消耗方面更加经济实惠。
中译英参考答案Unit 1A computer system consists of hardware system and software system. The hardware of the computer is usually divided into three major parts or three primary subsystems: the CPU, the memory subsystem, and the I/O subsystem.The CPU performs many operations and controls computer. The memory subsystem is used to store program being executed by the CPU, along with the program’s data. The I/O subsystem allows the CPU to interact with input and output devices such as the keyboard and monitor of a personal computer. The components of the computer are connected to the buses.The part of the computer that performs the bulk of data processing operations is called the central processing unit and is referred to as the CPU. In microcomputer, it is often called the microprocessor. The CPU is made up of three major parts: control unit, ALU, and register set.Memory is also known as internal memory or main memory. It refers to the circuits in the computer that hold whatever programs and data are available for immediate use by the CPU.I/O subsystem includes I/O devices and interface. There are a wide variety of I/O devices, such as mouse, printer, sensor, disk, and so on. Input-output interface provides a method for transferring information between internal storage and external I/O devices. Peripherals connected to a computer need special communication links for interfacing them with the CPU. The purpose of the communication link is to resolve the differences that exist between the central computer and each peripheral.Unit 2Storage hardware provides permanent storage of information and programs for retrieval by the computer. Hard disk drives store information in magnetic particles embedded in a disk. Usually a permanent part of the computer, hard disk drives can store large amounts of information and retrieve that information very quickly.Although fixed hard drive systems offer faster access and have a higher storage capacity than optical discs, optical disc systems use removable media –a distinct benefit. Optical discs –primary CDs and DVDs – are much more widely used than removable hard drive systems. They are the standard today for software delivery, as well as commonly used for storing high-capacity music and video files. There are also versions of both CD and DVD drives available for home audio and home theater use. Optical discs are commonly referred to as compact discs.CD and DVD discs are read by CD and DVD drives. The speed of a CD or DVD drive is rated as 24x, 32x, 36x, and so on. These labels describe how fast the drive is compared to the first version of that drive. For example, a 36x drive is 36 times the speed of the baseline unit that was originally manufactured. Most optical discs have a title and other text printed only on one side and they are inserted into the drive with the printed side facing up. When inserting such a CD or DVD, be careful not to get dirt, fingerprints, scratches, or anything else that might hinder light reflectivity on the disc’s surface.Unit 3<a> A program is a list of instructions or statements for directing the computer to perform arequired data processing task. Programming is a multistep process for creating that list of instructions.<b> It is important to understand the difference between a class and an object of that class.A class is simply a specification for creating objects. Thus, a single class may create multiple objects.<c> Java is an object-oriented, network-friendly high-lever programming language that allows programmers to build applications that can run on almost any operating system.<d> ActiveX is a set of controls, or reusable components that enables programs or content of almost any type to be embedded within a Web page. Whereas a Java must be downloaded each time you visit a Web site, with ActiveX the component is downloaded only once, then stored on your hard disk for later, repeated use.<e> Programming involves a great deal of creativity. The design is guide to the function or purpose of each component, but the programmer has great flexibility in implementing the design as code. No matter what language is used, each program component involves at least three major aspects: control structures, algorithms, and data structures.Unit 4The software system can be divided into two broad categories: application software and system software. Application software consists of the program for performing tasks particular to the machine’s utilization. In contrast to application software, system software comprises a large number of programs. These programs start up the computer and function as the principle coordinator of all hardware components and application software. Without system software loaded into RAM of your computer, your hardware and application software are useless.System software can be grouped into three basic parts: operating system, utility software, and language translators. The majority of an installation’s utility software consists of programs for performing activities that are fundamental to computer installations yet not included in the operating system. In a sense, utility software consists of software units that extend the capabilities of the operating system.A computer’s OS is the main collection of programs that manage its activities. The primary chores of an OS are management and control. The OS ensures that all actions requested by a user are valid and processed in an orderly fashion. It also manages the computer system’s resources to perform these operations with efficiency and consistency.Application software is the software designed to help you solve problems specific to business or perform specific business tasks. Application software then is the layer of software closest to you. Basically, there are four categories of application software: productivity software, business and specialty software, entertainment software and education/reference software.Unit 5A computer network is often classified as being either a local area network <LAN>, a metropolitan area network <WAN>, or a wide area network <W AN>. The connection of two or more networks is called an internetwork. The worldwide Internet is a well-known example of an internetwork.LANs are privately owned networks within a single building or campus of up to a few kilometers in size. They are widely used to connect personal computers and workstations incompany offices and factories to share resources and exchange information.In general, a given LAN will use only one type of transmission medium. Various topologies are possible for LANs. The most common LAN topologies are bus, ring and star.A MAN is basically a bigger version of a LAN and normally uses similar technology. MAN is designed to extend over an entire city. It may be a single network such as a cable television network, or it may be a means of connecting a number of LANs into a large network so that resources may be shared LAN-to-LAN as well as device-to-device. For example, a company can use a MAN to connect the LANs in all of its offices throughout a city.A W AN spans a large geographical area that may comprise a country, a continent, or even the world. It provides long-distance transmission of data, voice, image, and video information over large geographical area.In contrast to LANs, W ANs may utilize public leased, or private communication devices, usually in combinations, and can therefore span an unlimited number of miles.Unit 6Transmission media are used to transfer messages over a network. For instance, the transmission media used in a network may be a privately owned set of cables, the public phone lines, or a satellite system. Transmission media can either be wired or wireless.The three types of wired media most commonly used to carry messages are twisted-pair wire, coaxial cable, and fiber-optic cable. One of the most successful developments in transmission media in recent years has been fiber optics. Fiber-optic cable is commonly used for the high-speed backbone lines of a network, or for Internet infrastructure.Wireless transmission media have become especially popular in recent years. They support communications in situations in which physical wiring is impractical or inconvenient, as well as facilitate mobility. Wireless media are commonly used to connect devices to a network, to share information between computers, to connect wireless mice to a computer, and for handheld PCs, wireless phones, and other mobile devices. Radio signals transferred through the air are the heart of most types of wireless media. In addition to conventional broadcast radio application, the microwave, cellular, and satellite transmission media also use radio signals to transmit data. Radio transmissions require the use of a transmitter to send the radio signals through the air. A receiver <usually containing some type of antenna> accepts the date at the other end. When a device functions as both a receiver and transmitter, it is commonly called a transceiver or transmitter-receiver.Unit 7<a> Since many database systems users are not computer trained, developers hide the complexity from users through several levels of abstraction, to simplify user’s interactions with the system: physical level, logical level, and view level.<b> A database schema is specified by a set of definitions expressed by a special language called a data-definition language <DDL>. The result of compilation of DDL statements is a set of tables that is stored in a special file called data dictionary, or data directory.<c> The structured query language <SQL> is the most widely used and standard query language for relational database management systems. It is a kind of non-procedural language.<d> An entity is a "thing" or "object" in the real world that is distinguishable from otherobjects. For example, each person is an entity, and bank accounts can be considered to be entities. Entities are described in a database by a set of attributes.<e> Data warehouse is one of the newest and hottest buzzwords and concepts in the IT field and the business environment. A data warehouse is a logical collection of information——gathered from many differentoperational databases——that supports business analysis activities and decision-making tasks.Unit 8Animation is the term used to describe a series of graphical images that are displayed one after the other to simulate movement. Cartoons on television are one example of animation.Video differs from animation in that it usually begins as a continuous stream of visual information that is broken into separate images or frames when the video is recorded. When the frames are projected—typically at a rate of 30 frames per second—the effect is a smooth reconstruction of the original continuous stream of information. As you might imagine, at 30 frames per second, the amount of data involved in displaying a video during a multimedia presentation can require a substantial amount of storage space. Consequently, video data—like audio data—is often compressed. A variety of compression standards exist. Some of the most common video file formats are .avi, .mpeg, .mov, .rm.For multimedia presentation, video may be recorded using a standard <analog> video camera and then converted to digital form as it is input into a computer. Alternatively, the film can be recording digitally using a digital video camera. Streaming video is frequently used on Web pages to reduce file size. Similar to streaming audio, Streaming video files can begin playing once a portion of the video has been downloaded.Unit 9<a> AI is currently being applied in business in the form of knowledge systems, which use human knowledge to solve problems. The most popular type of knowledge-based system is the expert system. An expert system is a computer program that attempts to represent the knowledge of human experts in the form of heuristics. The term heuristic is derived from the same Greek root as the word eureka, which means "to discover".<b> The user interface enables the manager to enter instructions and information into the expert system and to receive information from it. The instructions specify the parameters that guide the expert system through its reasoning processing. The information is in the form of values assigned to certain variables.<c> The knowledge base contains both facts that describe the problem area and knowledge representation techniques that describe how the facts fit together in a logical manner. The term problem domain is used to describe the problem area.<d> An expert system, also called a knowledge-based system, is an artificial intelligence system that applies reasoning capabilities to reach a conclusion. Expert systems are excellent for diagnostic and prescriptive problems.<e> The DSS is not intended to replace the manager. The computer can be applied to the structured portion of the problem, but the manager is responsible for the unstructured portion——applying judgment or intuition and conducting analyses.Unit 10The linked list <see figure 1> consists of a series of nodes, which are not necessarily adjacent in memory. Each node contains the element and a link to a node containing its successor. We call this the next link. Thelast cell’s next link references null.To execute printList or find<x> we merely start at the first node in the list and then traverse the list by following the next links. This operation is clearly linear-time, as in the array implementation, although the constant is likely to be larger than if an array implementation were used. The findKth operation is no longer quite as efficient as an array implementation; findKth<i> takes O<i> time and works by traversing down the list in the obvious manner. In practice, this bound is pessimistic, because frequently the calls to findKth are in sorted order <by i>. As an example, findKth<2>, findKth<3>,findKth<4>, and findKth<6> can all be executed in one scan down the list.The remove method can be executed in one next reference change. Figure 2 shows the result of deleting the second element in the original list.The insert method requires obtaining a new node from the system by using a new call and then executing two reference maneuvers. The general idea is shown in figure 3. The dashed lineXUnit 11<a> A set is pure if all of its members are sets, all members of its members are sets, and so on. For example, the set containing only the empty set is a nonempty pure set.<b> A language is a describable set of finite strings, drawn from a fixed alphabet. A grammar is one way to "describe" the language. The grammar consists of a finite list of rules, where each rule replaces one substring with another. The string on the left must contain at least one nonterminal. The first string "produces" or "generates" the second. Thus a rule is also called a production.<c> A finite-state machine <FSM> or finite-state automaton〔FA is a mathematical abstraction sometimes used to design digital logic or computer programs. It is a behavior model composed of a finite number of states, transitions between those states, and actions, similar to a flow graph in which one can inspect the way logic runs when certain conditions are met.<d> Sometimes it is inconvenient or impossible to describe a set by listing all of its elements. Another useful way to define a set is by specifying a property that the elements of the set have in common. The notation P<x> is used to denote a sentence or statement P concerning the variable object x. The set defined by P<x> written {x | P<x>}, is just a collection of all the objects for which P is true.Unit 12<a> Because drawings are typically displayed in 3D, CAD is especially helpful in designing automobiles, aircraft, ships, buildings, electrical circuits <including computer chips>, and even clothing.<b> Computer-integrated manufacturing <CIM> is the manufacturing approach of using computers to control the entire production process. This integration allows individual processes toexchange information with each other and initiate actions. Through the integration of computers, manufacturing can be faster and less error-prone, although the main advantage is the ability to create automated manufacturing processes.<c> In addition to supporting decision making, coordination, and control, information system may also help managers and workers analyze problems, visualize complex subjects, and create new products.<d> Knowing the history and evolution of ERP is essential to understanding its current application and its future developments.<e> In addition to monitoring operational activities such as tracking the status of orders and inventory levels, enterprise system also improve organization-wide reporting and decision making.Unit 13<a> There are a wide variety of educational application programs available. Educational software is designed to teach one or more skills, such as reading, math, spelling, a foreign language, world geography, or to help prepare for standardized tests.<b> Electronic business <e-business> is the use of information technology and electronic communication networks to exchange business information and conduct transactions in electronic, paperless form.<c> Word processing software allows you to use computers to create, edit, store, and print documents. You can easily insert, delete, and move words, sentences, and paragraphs——without ever using an eraser.<d> What is a spreadsheet? Spreadsheet software takes its name from the accountant’s columnar worksheet, which it imitates. A spreadsheet is a worksheet consisting of a collection of cells formed by the intersection of rows and columns. Each cell can store one piece of information: a number, word or phrase, or formula.Unit 14<a> A geographic information system <GIS> is a system that captures, stores, analyzes, manages and presents data with reference to geographic location data. In the simplest terms, GIS is the merging of cartography, statistical analysis and database technology.<b> The GPS receiver uses the messages it receives to determine the transit time of each message and computes the distance to each satellite. These distances along with the satellites' locations are used to compute the position of the receiver. This position is then displayed, perhaps with a moving map display or latitude and longitude; elevation information may be included.<c> Virtual reality <VR> is a term that applies to computer-simulated environments that can simulate physical presence in the real world. Most current virtual reality environments are primarily visual experiences, displayed either on a computer screen or through special stereoscopic displays, but some simulations include additional sensory information, such as sound through speakers or headphones.Unit 15<a> The software development process is sometimes called the software development life cycle <SDLC>, because it describes the life of a software product from its conception to its implementation, delivery, use, and maintenance.<b> How can the CMM help your organization? There are three key roles the CMM plays. First, the CMM helps build an understanding of software process by describing the practices that contribute to a level of process maturity. The second role of the CMM is to provide a consistent basis for conducting appraisals of software processes. The CMM’s third key role is to serve as a blueprint for software process improvement.<c> The UML offers a standard way to write a system’s blueprints, including conceptual things such as business processes and system functions as well as concrete things such as programming language statements, database schemas, and reusable software components. The UML represents a collection of the best engineering practices that have proven successful in the modeling of large and complex systems.<d> Object modeling is a technique for identifying objects within the system environment and the relationships between those objects. The object-oriented approach to system development is based on several concepts, such as object, attribute, behavior, encapsulation, class, inheritance, polymorphism, persistence, etc.Unit 16"Security" is an all-encompassing term that describes all the concepts, techniques, and technologies to protect information from unauthorized access. There are several requirements for information security.Confidentiality: hiding data, usually with encryption, to prevent unauthorized viewing and access.Authenticity: the ability to know that the person or system you are communicating with is who or what you think it is.Access control: once a person or system has been authenticated, their ability to access data and use systems is determined by access controls.Data integrity: providing assurance that an information system or data is genuine. Availability: making sure that information is available to users in a secure way.To prevent unauthorized access, some type of identification procedure must be used. These vary from passwords to physical access object <access cards, etc.> to biometric devices that verify some type of personal characteristic, such as a fingerprint.Some of the most secure access control systems address both identification and authentication. Identification involves verifying that the person’s name or other identifying feature is listed as an authorized user; authentication refers to determining whether or not the person is actually who he or she claims to be.Unit 17A distributed system is a collection of independent computers which appear to the users of system as a single computer. Nearly all large software systems are distributed. For example, enterprise-wide business systems must support multiple users running common applications across different sites.Adistributed system encompasses a variety of applications, their underlying support software, the hardware they run on, and the communication links connecting the distributed hardware. The largest and best-known distributed system is the set of computers, software, and services comprising the World Wide Web, which is so pervasive that it coexists with and connects to mostother existing distributed systems. The most common distributed systems are networked client/server systems. Distributedsystems share the general properties described below.●Multiple nodes●Message passing or communication●Resource sharing●Decentralized control●Concurrency or parallelism●Fault tolerance●Heterogeneity●OpennessDistributedsystems have many inherent advantages, especially over centralized systems. Some applications are inherent distributedas well. In general, distributedsystems:●Yield higher performance●Allow incremental growth●Allow one user to run a program on many different machines in parallel●Provide higher reliability。
第七章：1.file server 文件服务器2.carrier sense 载波检测，载波监听3.protocol suite 协议组，协议集4.peer-to-peer model 对等模型5.bus topology network 总线拓扑网络6.inter-machine cooperation 机器间合作，计算机间合作7.Ethernet protocol collection 以太网协议集8.proprietary network 专有网络9.utility package 实用软件包，公用程序包10.star network 星形网络11.局域网 local area network (LAN)12.令牌环 token ring13.无线网络 wireless network14.封闭式网络 closed network15.环形拓扑结构 ring topology16.客户机／服务器模型 client/server model17.网络应用程序 network application18.进程间通信 interprocess communication19.打印服务器 print server 20.广域网 wide area network (WAN)1.routing path 路由选择通路2.dual-ring topology 双环形拓扑结构3.extended star topology 扩展星形拓扑结构4.backbone network 基干网，骨干网5.mesh topology 网格拓扑结构6.同轴电缆 coaxial cable7.逻辑拓扑结构 logical topology8.无冲突连网环境collision-free networking environment9.树形拓扑结构 tree topology10.目的地节点 destination node1.destination address 目的地址2.performance degradation 性能退化（或降级）3.four-interface bridge 4接口网桥mon bus 公共总线，公用总线5.数据链路层 data-link layer6.协议转换器 protocol converter7.开放式系统互连OSI (Open SystemsInterconnection)8.物理地址 physical address第八章：1.cell phone 蜂窝电话，移动电话，手机2.IP address 网际协议地址，IP地址3.autonomous system 自主系统4.dial-up connection 拨号连接work identifier 网络标识符6.binary notation 二进制记数法7.mnemonic name 助记名，缩写名8.Internet-wide directory system 因特网范围的目录系统 server 名称服务器10.Internet infrastructure 因特网基础结构11.助记地址 mnemonic address12.网吧 cyber cafe13.宽带因特网访问 broadband Internet access14.顶级域名 top-level domain (TLD)15.因特网编址 Internet addressing16.点分十进制记数法 dotted decimal notation17.因特网服务提供商 Internet service provider (ISP)18.专用因特网连接 dedicated Internet connection19.主机地址 host address20.硬件与软件支持 hardware and software support1.incoming message 来报，到来的报文2.application layer 应用层3.utility software 实用软件4.sequence number （顺）序号，序列号5.remote login capabilities 远程登录能力6.端口号 port number7.软件例程 software routine8.传输层 transport layer9.文件传送协议 FTP（File Transfer Protocol）10.万维网浏览器 Web browser1.wildcard character 通配符2.Copy command 复制命令3.search operator 搜索算符4.home page 主页5.回车键 Enter key6.搜索引擎 search engine7.嵌入代码 embedded code8.超文本标记语言 Hypertext Markup Language第九章：1.server farm 大型机服务器2.access protocol 存取协议，访问协议3.storage area network 存储区域网（络）4.high-throughput computing 高吞吐（量）计算5.server cluster 服务器集群6.public cloud 公共云7.grid computing 网格计算8.security-aware cloud architecture 具有安全意识的云体系结构9.social networking 社交网络10.utility computing 效用计算11.云计算提供商 cloud computing provider12.存储芯片 memory chip13.基于内部网的私有云 intranet-based private cloud14.网络带宽 network bandwidth15.混合云 hybrid cloud16.磁盘阵列 disk array17.软件即服务 Software as a Service (SaaS)18.集群计算 cluster computing 19.虚拟化计算机资源 virtualized computer resources20.多核处理器 multi-core processorputer vision 计算机视觉2.ubiquitous computing 普适计算mand line 命令行4.data logging system 数据记录（或登录）系统5.augmented reality 增强现实6.移动网络 mobile network7.平板电脑 tablet computer8.物联网 Internet of Things9.智能电网 smart power grid10.传感器融合 sensor fusion1.notebook computer 笔记本2.wireless hotspot 无线热点3.Short Message Service 短信（服务）4.wearable computer 可穿戴计算机，穿戴式计算机5.移动电话 mobile phone6.条形码阅读器 barcode reader7.网站 Web site8.智能手机 smart phone第十章：1.backup system 备份系统2.encryption key （加密）密钥3.data confidentiality 数据机密性4.system vulnerability 系统脆弱性，系统脆弱之处5.unauthorized access 未经授权的访问，越权存取6.intrusion detection system 入侵检测系统7.after-action recovery 事后恢复8.software piracy 软件侵权9.authorized user 特许用户10.data unit 数据单元，数据单位11.软件版本 software version12.数据完整性 data integrity13.系统崩溃 system crash14.病毒检查软件 virus-checking software15.综合安全策略 comprehensive security strategy16.软件配置管理 software configuration management17.故障隔离 fault isolation18.统计数据库 statistical database 19.保密的加密算法 secure encryption algorithm20.数据流 data stream1.phishing attack 网络钓鱼攻击2.graphics card 显（示）卡3.heuristic analysis 试探性分析4.infected file 被感染文件5.virus dictionary 病毒字典6.数据捕获 data capture7.恶意软件 malicious software8.病毒特征代码 virus signature9.防病毒软件 antivirus software10.内存驻留程序 memory-resident program1.maintenance hook 维护陷阱2.multipartite virus 多成分病毒3.authentication procedure 验证过程，认证过程4.instant messaging 即时通信，即时消息5.系统登录程序 system login program6.逻辑炸弹 logic bomb7.多威胁恶意软件 multiple-threat malware8.源代码 source code第十一章：1.mailing list 邮件发送清单，邮件列表2.proprietary software 专有软件 line 抄送行4.bcc line 密送行5.forwarded e-mail message 转发的电子邮件6.e-mail convention 电子邮件常规7.click on an icon 点击图标8.confidential document 密件，秘密文件9.classified information 密级信息10.recovered e-mail message 恢复的电子邮件11.常用情感符 commonly used emoticon12.已删除电子邮件 deleted e-mail13.电子系统 electronic system14.附件行 Attachments line15.版权法 copyright law16.电子邮件网规 e-mail netiquette17.信息高速公路 information superhighway18.签名文件 signature file19.电子数据表程序 spreadsheet program20.文字处理软件 word processor1.web-authoring software 网络写作软件2.template generator 模版生成程序3.navigation page 导航页面4.corporate logo 公司标识5.splash page 醒目页面，过渡页6.导航条 navigation bar7.节点页面 node page8.网站地图 site map9.可用性测试 usability testing10.图形交换格式 gif（Graphics Interchange Format）1.message board 留言板，消息板2.software vendor 软件供应商，软件厂商3.anonymous message 匿名消息4.video clip 视频剪辑，视频片段5.过滤软件 filtering software6.版权侵犯 copyright infringement7.网络中立性 network neutrality8.网络运营商 network operator第十二章：1.customized marketing strategy 定制的营销策略2.B2G transaction 企业对政府交易3.dial-up modem 拨号调制解调器4.dot-com bust 网络不景气5.smart card 智能卡6.digital piracy 数字盗版7.dot-com boom 网络繁荣8.C2C transaction 消费者对消费者交易9.Web auction site 拍卖网站10.fingerprint reader 指纹读取器11.射频识别装置radio-frequency identification (RFID) device12.电子数据交换 electronic data interchange (EDI)13.库存管理技术 inventory management technology14.知识产权 intellectual property15.条形码 bar code16.货币兑换 currency conversion17.电子图书 electronic book18.视网膜扫描仪 retina scanner19.个人数字助理 personal digital assistant (PDA)20.企业对企业电子商务 B2B electronic commerce1.software suite 软件套件2.text box 文本框3.virtual checkout counter 虚拟付款台4.static catalog 静态目录5.browser session 浏览器会话期6.动态目录 dynamic catalog7.购物车软件 shopping cart software8.供应链 supply chain9.企业资源计划软件enterprise resource planning (ERP) software10.税率 tax rate1.privacy policy 隐私政策2.identity theft 身份（信息）盗取3.affiliate marketing 联属网络营销，联盟营销4.postal money order 邮政汇票5.零售网站 retail website6.信用卡 credit card7.货到付款 cash on delivery8.安全套接层 Secure Sockets Layer。
第一章1.计算机的发展经历了机械式计算机、（B）式计算机和电子计算机三个阶段。
（A）电子管（B）机电（C）晶体管（D）集成电路2.英国数学家巴贝奇曾设计了一种程序控制的通用（D）。
（A）加法器（B）微机（C）大型计算机（D）分析机3. 1939年，美国爱荷华州立大学研制成功了一台大型通用数字电子计算机（D）。
（A）ENIAC （B）Z3 （C）IBM PC （D）ABC4.爱德华•罗伯茨1975年发明了第一台微机（C）。
（A）Apple II （B）IBM PC （C）牛郎星（D）织女星5.1981年IBM公司推出了第一台（B）位个人计算机IBM PC 5150。
（A）8 （B）16 （C）32 （D）646.我国大陆1985年自行研制成功了第一台PC兼容机（C）0520微机。
（A）联想（B）方正（C）长城（D）银河7.摩尔定律指出，微芯片上集成的晶体管数目每（C）个月翻一番。
（A）6 （B）12 （C）18 （D）248.第四代计算机采用大规模和超大规模（B）作为主要电子元件。
（A）微处理器（B）集成电路（C）存储器（D）晶体管9.计算机朝着大型化和（C）化两个方向发展。
（A）科学（B）商业（C）微机（D）实用10.计算机中最重要的核心部件是（A）。
（A）CPU （B）DRAM （C）CD-ROM （D）CRT11.计算机类型大致可以分为：大型计算机、（A）、嵌入式系统三类。
（A）微机（B）服务器（C）工业PC （D）笔记本微机12.大型集群计算机技术是利用许多台单独的（D）组成一个计算机群。
（A）CPU （B）DRAM （C）PC （D）计算机13.（C）系统是将微机或微机核心部件安装在某个专用设备之内。
（A）大型计算机（B）网络（C）嵌入式（D）服务器14.冯结构计算机包括：输入设备、输出设备、存储器、控制器、（B）五大组成部分。
（A）处理器（B）运算器（C）显示器（D）模拟器15.在冯•诺伊曼计算机模型中，存储器是指（A）单元。
计算机专业英语（第四版）课后习题答案Unit 1[Ex 1] 1. F 2. T 3. T 4. F 5. T 6. T 7. T 8. T 9. T 10. F [Ex 2] 1. input, storage, processing, and output 2. power; speed; memory3. central processing unit4. internal; primary; memory5. keyboard; central processing unit; main memory; monitor[Ex 3] A. 1. F 2. D 3. G 4. C 5. B 6. A 7. E 8. HB. 1. user 2. monitor 3. data 4. keyboard 5. data processing6. information7. computer8. memory[Ex 4] 1. input device 2. screen, screen 3. manipulates 4. instructions 5. retrieve6. code7. hard copy8. Function[Ex. 5] 新处理器开始IT技术的新时代New Processors Open New Era of IT Technologies Last week, Intel introduced to the public in Russia and other CIS countries a family of processors Intel Xeon E5-2600. They are more powerful and reliable and, importantly, are very economical in terms of energy consumption. Their presence opens a new era in the field of IT technologies and means that the cloud technology is getting closer.These processors are primarily designed for servers, data centers (DPC) and supercomputers. The emergence of this class of devices is not accidental. According to the regional director of Intel in Russia and other CIS states Dmitri Konash who spoke at the event, the market of IT-technology is developing so rapidly that, according to forecasts, by 2015 there will be 15 billion devices connected to the Internet, and over 3 billion of active users.上周，英特尔公司向俄罗斯和其它独联体国家的公众推出了英特尔XeonE5-2600系列处理器，它们更加强大可靠，尤其是在能量消耗方面更加经济实惠。
计算机网络技术实用教程(第四版)习题答案-标准化文件发布号：（9456-EUATWK-MWUB-WUNN-INNUL-DDQTY-KII计算机网络技术实用教程（第四版）习题答案第一章答案一、名词解释1. 计算机网络答案：计算机网络是将分布在不同地理位置上的具有独立工作能力的计算机、终端及其附属设备用通信设备和通信线路连接起来，并配置网络软件，以实现计算机资源共享的系统。
2. 单播答案：单播是指发送的信息中包含明确的目的地址，所有结点都检查该地址。
如果与自己的地址相同，则处理该信息，如果不同，则忽略3. 组播组播是将信息传送给网络中部分结点。
4. 广播答案：广播是指在发送的信息中使用一个指定的代码标识目的地址，将信息发送给所有的目标结点。
当使用这个指定代码传输信息时，所有结点都接收并处理该信息。
5. 网络拓扑答案：网络拓扑是指计算机网络的物理连接方式叫做网络的拓扑结构。
6. 带宽答案：在通信线路上传输模拟信号时，将通信线路允许通过的信号频带范围称为线路的带宽。
二、填空题1．广域网、城域网、局域网、接入网。
2．广播网络、点对点网络3．单播、组播、广播4．资源子网、通信子网5．汇聚层、接入层6．传输的距离、传输技术、使用的线路、带宽7. 发送时延、传播时延、处理时延三、选择题1-5 BAAAB 6-9DCBB四、简答题1. 计算机网络组成的三要素是什么答案：一个计算机网络必须具备以下3个基本要素：（1）至少有两个具有独立操作系统的计算机，且它们之间有相互共享某种资源的需求。
（2）两个独立的计算机之间必须用某种通信手段将其连接。
（3）网络中的各个独立的计算机之间要能相互通信，必须制定相互可确认的规范标准或协议。
2. 计算机网络具有哪些功能？答案：计算机网络的功能有：（1）数据通信（2）计算机系统的资源共享（3）进行数据信息的集中和综合处理（4）能均衡负载，相互协作（5）提高了系统的可靠性和可用性（6）进行分布式处理3. 计算机网络的发展可划分为几个阶段每个阶段各有何特点答案：（1）具有通信功能的单机系统特点：单机系统中，主计算机负担较重，既要进行数据处理，又要承担通信功能。
第一部分《计算机英语》参考译文第一单元：计算机与计算机科学课文A：计算机概览一、引言计算机是一种电子设备，它能接收一套指令或一个程序，然后通过对数字数据进行运算或对其他形式的信息进行处理来执行该程序。
要不是由于计算机的发展，现代的高科技世界是不可能产生的。
不同类型和大小的计算机在整个社会被用于存储和处理各种数据，从保密政府文件、银行交易到私人家庭账目。
计算机通过自动化技术开辟了制造业的新纪元，而且它们也增强了现代通信系统的性能。
在几乎每一个研究和应用技术领域，从构建宇宙模型到产生明天的气象报告，计算机都是必要的工具，并且它们的应用本身就开辟了人们推测的新领域。
数据库服务和计算机网络使各种各样的信息源可供使用。
同样的先进技术也使侵犯个人隐私和商业秘密成为可能。
计算机犯罪已经成为作为现代技术代价组成部分的许多风险之一。
二、历史第一台加法机是法国科学家、数学家和哲学家布莱斯?帕斯卡于1642年设计的，它是数字计算机的先驱。
这个装置使用了一系列带有10个齿的轮子，每个齿代表从0到9的一个数字。
轮子互相连接，从而通过按照正确的齿数向前转动轮子，就可以将数字彼此相加。
17世纪70年代，德国哲学家和数学家戈特弗里德?威廉?莱布尼兹对这台机器进行了改良，设计了一台也能做乘法的机器。
法国发明家约瑟夫―玛丽?雅卡尔，在设计自动织机时，使用了穿孔的薄木板来控制复杂图案的编织。
在19世纪80年代期间，美国统计学家赫尔曼?何勒里斯，想出了使用类似雅卡尔的木板那样的穿孔卡片来处理数据的主意。
通过使用一种将穿孔卡片从电触点上移过的系统，他得以为1890年的美国人口普查汇编统计信息。
1、分析机也是在19世纪，英国数学家和发明家查尔斯?巴比奇，提出了现代数字计算机的原理。
他构想出旨在处理复杂数学题的若干机器，如差分机。
许多历史学家认为，巴比奇及其合伙人，数学家奥古斯塔?埃达?拜伦，是现代数字计算机的真正先驱。
巴比奇的设计之一，分析机，具有现代计算机的许多特征。
ANDREW S. TANENBAUM 秒，约533 msec.----- COMPUTER NETWORKS FOURTH EDITION PROBLEM SOLUTIONS 8. A collection of five routers is to be conn ected in a poi nt-to-poi nt sub net.Collected and Modified By Yan Zhe nXing, Mail To: Betwee n each pair of routers, the desig ners may put a high-speed line, aClassify: E aEasy, M ^Middle, H Hard , DaDeleteGree n: Importa nt Red: Master Blue: VI Others:Know Grey:—Unnecessary ----------------------------------------------------------------------------------------------ML V Chapter 1 In troductio nProblems2. An alter native to a LAN is simply a big timeshari ng system with termi nals forall users. Give two adva ntages of a clie nt-server system using a LAN.(M)使用局域网模型可以容易地增加节点。
如果局域网只是一条长的电缆，且不会因个别的失效而崩溃(例如采用镜像服务-------------------------------------------器)的情况下，使用局域网模型会更便宜。
