计算机专业英语教程(第4版)全书译文

《计算机英语（第4版）》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。

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 (WAN). 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 different operational 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. The last 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 line represents the old next reference.figure 1figure 2figure 3Unit 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 whichP 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 to exchange 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 areprimarily 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.A distributed 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 most other existing distributed systems. The most common distributed systems are networked client/server systems. Distributed systems share the general properties described below.●Multiple nodes●Message passing or communication●Resource sharing●Decentralized control●Concurrency or parallelism●Fault tolerance●Heterogeneity●OpennessDistributed systems have many inherent advantages, especially over centralized systems. Some applications are inherent distributed as well. In general, distributed systems:●Yield higher performance●Allow incremental growth●Allow one user to run a program on many different machines in parallel●Provide higher reliability。

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。

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A growi‎n g numbe‎r of Web sites‎incor‎p orat‎e multi‎m edia‎, as do compu‎t er softw‎a re and consu‎m er inter‎f aces‎,such as ATM machi‎n es and infor‎m atio‎n kiosk‎s,（像自动取款‎机和信息亭‎那样的越来‎越多的We‎b站点配备‎了多媒体（如计算机多‎媒体软件，客户接口也‎配备了多媒‎体）A neces‎s ary featu‎r e of a DTP packa‎g e, there‎f ore, is a zoom facil‎i ty which‎displ‎a ys a porti‎o n of the docum‎e nt at a large‎r size than norma‎l so as to displ‎a y it at somet‎h ing much close‎r to the resol‎u tion‎of the final‎print‎e d produ‎c t（因此，DTP软件‎包的一个必‎备特征就是‎有缩放工具‎，它可以用比‎正常情况更‎大的尺寸显‎示文件的某‎一部分，从而以更接‎近最终印刷‎结果的分辨‎率来显示这‎些内容）A newer‎scrip‎t ing langu‎a ge incre‎asing‎ly more popul‎a r is PHP and ASP.而更通用的‎，比较新的脚‎本语言是P‎H P 和ASP。

Unit 8 Computer NetworkingText 1 Data CommunicationsThe end equipment can be computers, printers, keyboards, CRTs, and so on.They are either generates the digital information for transmission or uses the received digital data. This equipment generally operates digital information internally in word units.DTE is data terminal equipment. A station controller STACO is the corresponding unit at the secondaries. At one time, the DTE was the last piece of equipment that belonged to the subscriber in a data link system. Between the DTEs, first is the modem, and then is the communications equipment. The communication equipment is owned and maintained by Telco. Data communications equipment DCE accepts the serial data stream from the DTE. And DCE converts it to some form of analog signal suitable for transmission on voice-grade lines. At the receive end, the DCE performs the reverse function. It converts the received analog signal to a serial digital data stream. The simplest form of DCE is a modem modulator/demodulator or data set. At the transmit end, the modem can be considered a form of digital-to-analog converter.While at the receive end, it can be considered a form of analog-to-digital converter.参考译文数据通信终端设备可以是计算机、打印机、键盘、CRT等;它们可以生成要发送的数字信息,也可以使用所接收的数字数据;这种设备通常在内部以字为单位处理数字信息;DTE一般称为数据终端设备;辅助设备一方的相应设备是工作站控制器STACO;同时,DTE也是数据链路系统中属于用户端的最后一个设备;在两个DTE之间,先是调制解调器,接着是属于Telco电话公司维护的通信设备;数据通信设备DCE从DTE接收串行数据流,并将其转换成适合于在语音线路上发送的某种模拟信号形式;在接收端,DCE完成相反的功能,把接收到的模拟信号转换成串行数字数据流;最简单的DCE是调制解调器或数据传送机;在发送端,调制解调器可以视为一种数/模转换器,而在接收端则可视为一种模／数转换器;Text 2 Architecture of Computer NetworksComputer network is a complex unit, it consists of two or more connected computing units. It is used for the purpose of data communication and resource sharing. Design of a network and its logical structure should comply with a set of design principles. They include: the organization of functions, the description of data formats and procedure.In the following two sections we will discuss two important network architectures, the OSI reference model and the TCP/IP reference model.(1)the OSI reference modelThe OSI open systems interconnection model was created by the ISO. This model is a foundation for comparing protocols; However, more protocols deviate from the rules set up by the OSI model.The OSI model has seven layers. Note that the OSI model itself is not a network architecture.It just tells what each layer should do. However, ISO has also produced standards for all the layers. Each one has been published as a separate international standard.(2)the TCP/IP reference modelTCP/IP is a communication protocol; it provides many different networking services.The TCP/IP Internet protocol suite is formed from two standards: the TCP Transmission Control Protocol and the IP Internet Protocol. TCP means it is on the transport layer. IP means it is on the network layer. On top of the transport layer is the application layer. It contains all the higher-level protocols. The early ones included virtual terminal TELNET, file transfer FTP, electronic mail SMTP and domain name service DNS.As we know, TCP/IP is the foundation of the Internet.These protocols are continually changing and evolving to support the needs of the user community.参考译文计算机网络结构计算机网络是由两个或多个计算机设备互连而成的一种复合系统,它用于数据通信和资源共享;网络设计及其逻辑结构应该遵循一套设计原则,其中包括：功能的组织以及数据格式和过程的说明;在下面的两小节里,我们将讨论两个重要的网络体系结构,即OSI参考模型和TCP/IP参考模型;(1)OSI参考模型OSI模型开放系统互联参考模型是由国际标准化组织ISO开发的一个建议;相对于其他协议来说,此种模式为基础模式;然而,更多的协议是背离OSI模型的;OSI模型有7层;应该注意的是,OSI模型本身并不是一种网络体系结构,它只是说明每一层应该做什么;然而,ISO还是对各层制定了标准,每一层都是作为一个单独的国际标准来颁布的;(2)TCP/IP参考模型TCP/IP参考模型是一种传输协议,提供了许多不同的网络服务;TCP/IP协议组由TCP传输控制协议和IP网际协议两部分组成;TCP表明是处于传输层,IP意为是在网络层;在传输层上面是应用层;应用层包括所有高层协议;早期的协议包括虚拟终端TELNET、文件传送协议FTP、电子邮件SMTP和域名服务DNS;现在我们知道,TCP/IP协议是因特网的基础;这些协议在用户们的支持下不断地改变和进化着;Text 3 Local Area NetworkA LAN Local area data network is a group of computers. The work devices connected together usually within the same building. By definition, the connections must be high-speed and relatively inexpensive . token ring or Ethernet. For example, a LAN may be used to interconnect workstations distributed around offices within a single building or a group of buildings such as a university campus.LANs consist of carefully selected groups of components hardware and software. They are configured for the specific requirements of the organization. A LAN is generally limited to the size of a department or an organization. And a LAN often consists of 2 to 100 devices. LANs usually contain resources such as servers, printers, and connections to other networks through internetworking devices. The internetworking devices include switches and routers.In the next section we will discuss the structure of the different types of LAN.(1)TopologyMost wide area networks, such as the PSTN, use a mesh sometimes referred to as a network topology. With LANs, however, the limited physical separation of the subscriber DTEs allows simpler topologies to be used. The four topologies in common use are star, bus, ring and hub.The most widespread topology for LANs designed to function as data communication subnetworks for the interconnection of local computer-based equipment is the hub topology. It is a variation of the bus andring.(2)Transmission mediaTwisted pair, coaxial cable and optical fibre are the three main types of transmission medium used for LANs.(3)Medium access control methodsTwo techniques have been adopted for use of the medium access control in the LANs. One is carrier-sense-multiple-access with collision detection, and the other is control token.参考译文局域网局域数据网局域网由若干计算机组成;通常是一幢楼内的工作设备被连接在一起;通过定义可知,这种连接一定是高速并且相对廉价的如：令牌网和以太网;例如,一个局域网可以把一幢楼里或像大学校园内楼群里的各个办公室的工作站连在一起;局域网是由精心挑选的各组设备硬件和软件构成的;它们根据组织的各种特殊需要来配置;局域网的大小一般限制在一个部门或者一个组织,由2～100台电脑组成;局域网经常包含一些资源,如一些服务器和打印机,而且可以通过网络设备与其他的网络连接;这些网络设备包括交换机和路由器等;接下来,我们将讨论不同类型局域网的结构;(1)拓扑结构大多数广域网,如公共电话交换网PSTN,使用网状有时称为网络拓扑结构；而局域网由于用户数据终端设备相距很近,可采用简单的拓扑结构;常用的有星形、总线、环形和集线器等4种拓扑结构;应用最广的、用于互连本部门计算机设备以进行数据通信的局域网拓扑结构是集线器拓扑结构;这种拓扑结构是总线和环形拓扑结构的变种;(2)传输媒体双绞线、同轴电缆和光纤是局域网采用的3种主要传输媒体;(3)媒体访问控制方法局域网中采用了两种媒体访问控制技术,一种是载波侦听多路访问／冲突检测技术CSMA/CD,另一种是令牌控制技术;Text 4 InternetThe Internet is used by millions of people across the world to communicate business and personal information. The Internet is huge. Then we will talk about the difference of “an internet”and “ the Internet”.An internet note the lower case "i" is a computer network. It allows computers with distinctive software and hardware to communicate. Many kinds of computers can be connected to an internet. Each computer can serve a specialized role. It offers a wide variety of services to its users.The Internet is specific kind of internet. In The Internet Passport, the Internet will be defined as the network of networks. It follows a set of rules known as the "Internet Protocol IP suite".But what does this mean to you It means that any computer that is connected to the Internet can communicate with any other Internet computer. From the user's perspective, this works much like the telephone system works. You can dial from your phone to any other phone on the system, no matter what kind of telephone you have; you only need to know the phone number of the person you want to reach.With an Internet connection you can get some of the basic services available are:•E-mail. It’s a fast, easy, and inexpensive way to communicate with other Internet users around the world.•Telnet. It allows a user to log into a remote computer as though it were a local system.•FTP. It allows a user to transfer virtually every kind of file that can be stored on a computer from one Internet-connected computer to another.•Usenet news. It’s a distributed bulletin board which offers a combination news and discussion service on thousands of topics.•World Wide Web . It’s a hypertext interface to Internet information resources. Also, through an Internet connection, you can:•access online library catalogs.•copy computer files or software from archives.•access databases for teaching or research.•obtain free electronic books.•use educational and information services.•use directory services to find Internet users.•access supercomputer sites.It was estimated that at this rapid growth everyone in the world would have an e-mail address in the near future.参考译文互联网因特网是世界上很多人用来进行商业贸易和个人信息交流的网络,它非常巨大;接下来,我们将讨论互联网及因特网;互联网internet注意小写字母i是一种计算机网络,该网络上的计算机在通信时可以使用不同的软件和硬件;多种计算机都可以连入互联网,每台计算机都可以有一独特作用;一个互联网可以向它的用户提供各式各样的业务;因特网Internet是一种专用互联网;因特网在它的证书中定义为网络的网络,该网络使用了一组叫做互联网协议IP组的规则;但对你来说,这意味着什么呢这表明连接到因特网上的计算机可以与因特网上任何其他计算机通信;从用户的角度来看,其工作方式很像电话系统的工作方式;在电话系统内,可以从你的电话机拨打任何其他电话,而不管你使用什么样的电话机,你只需知道对方的电话号码即可;你可以通过因特网得到的基本服务如下：•电子邮件;它是与世界范围内的因特网用户进行联系的一种快速、方便、廉价的交流方式;•远程登录;允许用户连接到远程计算机上,就像这台远程计算机是本地机一样;•文件传输协议;该协议可以将存储在计算机上的各种文件,从因特网上的一台计算机传送给另一台计算机;•新闻组网络系统;一种分布式的电子公告牌,它能提供有关上千种话题的新闻和讨论服务;•万维网;一种因特网信息资源的超文本界面;•访问在线图书馆目录;•从计算机档案库存储器中拷贝文件或软件;•访问教学或科研数据库;•获取免费电子图书;•使用教育和信息服务;•使用目录服务以查找因特网用户;•访问超级计算机站点;估计以这样的高速发展,在不久的将来世界上每个人都将拥有至少一个电子邮件地址;Text 5 The World Wide WebThe World Wide Web also known as or Web is one of the fastest-growing Internet software applications. It is an architectural framework. It linked documents spread out over thousands of machines for accessing all over the Internet.The World Wide Web ties the computers together into a vast collection of interactive multimedia resources. The is a way of exchange information between computers on the Internet.The Web is built around hypertext and hypermedia. A hypertext document has certain keywords or phrases linked to other online documents. A person reading a hypertext document about mobile phone, for example, might be able to select the highlighted word “Nokia 3310”, and he call up another document giving more information about that particular type. With documents intertwined by links into a web of information, you can select paths to browse online resources, a process often referred to as surfing.Hypermedia extends the concept of hypertext to other forms of information. They include: images, sounds, and even video clips. If a person read a hypermedia document about mobile phones, then he might select a video show of a phone and hear the ring of it.The World Wide Web also subsumes previous Internet information systems such as Gopher and FTP. These resources can still be accessed through the Web. But the Web offered by these more restricted connection methods. Now the Web provides a wealth of additional capabilities.Thousands of computers around the world are now connected to the Web. They offer a huge variety of information and services to visitors. These online documents are generally referred to as pages. They are composed and supported by various people and organizations. Web pages are available for an amazing variety of tasks ranging from the playful to the serious. You can get many services access Web pages. For example, you can search database of mailing lists, you can see pictures of your favorite band and their concert schedule, or you can take a “tour” through a foreign country. Thousands of links to new services are added to the Web each day, and its growth has been explosive.参考译文万维网万维网又称或Web是因特网上发展最快的应用软件之一;它是一种结构化框架,用于访问遍布在因特网上的成千上万台机器中的链接文档;万维网把这些计算机连接成了一个巨大的交互式多媒体资源库,它是因特网上的计算机之间进行信息交流的一种方式;Web是用超文本和超媒体设计的;超文本文档中的一些关键词或短语被链接到了其他的在线文档中;例如,某人在阅读一篇有关移动电话的超文本文档时,如果他选择高亮显示的词“诺基亚3310”,就能链接到另一篇有关这一类型移动电话的文章,从而可以获取更多的信息;网络文章通过链接形成了一个网络信息资源库,用户可以选择路径来浏览这些在线资源,这种行为通常被称为“网上冲浪”;超媒体将超文本的概念扩展到了其他的信息形式,其中包括图片、声音,甚至是录像剪辑;在超媒体文档中阅读有关移动电话的文章时,读者可以选择关于该电话的视频演示,还能听见铃声;万维网也包括了以前的因特网信息系统,如Gopher 和FTP;这些资源仍然可以通过网络访问,但是以前那些连接方式的局限性很大,现在的网络提供了许多先辈们没能提供的功能;现在世界上成千上万的计算机都连接到了网络上,而且为访问者提供了相当多的信息和服务;这些由不同的人和组织编写和支持的在线文档被称为网页;Web网页可以跨越从诙谐到严肃的各种风格;通过访问网页,用户可以查看邮件数据库,查阅自己喜爱的乐队的图片和他们的演出时间表,或去国外周游一圈;现在每天都会增加上千种新的服务链接,万维网已经飞速发展起来了;。

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。

翻译：1、C++’s advantages include strong typing, operator overloading, and less emphasis on the preprocessor.C++的优点包括强类型，运算符重载和较少地强调预处理器。

2、A program instruction or a piece of data is stored in a specific primary storage location called an address.程序指令和数据是存储在主存中一个特殊的位置，称为地址空间3、A high-level language is an artificial language with which we can write various instructions. This is possible not because computer processors are now so technologically advanced that they can ‘understand’ these langu ages. You should translate from programming languages into machine language which can be understood by the computer processors. Compilers can accomplish this task. This does mean that a high-level language program is not directly executable: it must be compiled to produce processor program, which is executable.高级语言是一门人工的我们可以写入各种各样指令的语言。

《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。

第4章操作系统第一部分阅读和翻译A部分 Windows 71. 简介Windows 7是微软最新发布的windows版本,这一系列微软制造的操作系统主要用于个人电脑,其中包括家庭和商业台式电脑、笔记本电脑、上网本、平板电脑、和媒体中心电脑。

(见图4.1)Windows 7于2009年7月22日开始生产,并在2009年10月22日零售,这个时间距其推出其前任Windows Vista不到三年时间。

与Windows 7相对应的Windows server 2008 R2,也是同年发布。

不像其前一操作系统vista，windows7 引入了大量的新特性，更集中于增量升级的windows线，目标是兼容已经在vista中兼容的应用程序和硬件。

微软在2008年的报告中关注于对于多点触控的支持，以及一个重新设计的windows shell和一个新的任务栏，并将其称之为Superbar，还有一个称之为家庭组的网络系统，注重性能改进。

之前版本的windows 系统中的一些标准的应用程序，包括windows日历，windows邮件，windows movie maker，和windows相片画廊在windows 7中并没有包含进来，而大多数是作为Windows Live Essentials套件单独免费进行提供的。

2. 发展最初，微软计划用一个代号为Blackcomb的windows版本来继承Windows XP(代号惠斯勒)和Windows Server 2003。

微软计划在Blackcomb中设计的主要功能包括在搜索中的加强，查询数据以及一个先进的存储命名系统。

然而，一个临时的，更小的，代号为Longhorn 的版本在2003年发布了。

微软在2003年中旬推迟发布了Blackcomb，但是Longhorn获得了大部分当初试图在Blackcomb中实现的特性。

在2003年，相继有三个主要病毒暴露了windows操作系统的一些漏洞，微软改变了其的发展重点，搁置了Longhorn的主要开发工作，主要开发windows xp和windows server 2003的服务包。