《计算机英语(第4版)》课后练习参考答案

1、Unit Four/Section BI.Fill in the blanks with the information given in the text:1.Information engineering emphasizes a modeling tool called entity relationship diagrams.2.One of the disadvantages of model-driven development is the long duration of projects.3.Unlike structured analysis and design and

2、information engineering, object-oriented analysis and design attempt to emerge the data and process concerns into singular constructs called objects.4.Unlike logical models, physical models show not only what a system is or does , but also how the system is physically and technically implemented.II.

3、Translate the following terms or phrases from English into Chinese and vice versa:1.check box 复选框，选择框，校验框2.structured design 结构化设计3.building block 积木块，构建模块，构件4.database schema 数据库模式5.radio button 单选（按）钮6.系统建模技术 system modeling technique7.模型驱动开发 model-driven development8.数据流程图 data flow diagram9.下拉式菜

4、单 drop-down (或pull-down) menu10.滚动条 scroll barUnit Five: Software ProcessUnit Five/Section AI.Fill in the blanks with the information given in the text:1. New software may be developed from scratch or through the use of existing systems and off-the-shelf software or system components.2. The three ge

5、neric process models discussed in the text are often complementary rather than mutually exclusive, especially for large system development.3. The waterfall model is so named because of the cascade from one phase to another in the software development process.4. The fundamental development activities

6、 of the waterfall model are requirements analysis and definition, system and software design, implementation and unit testing, integration and system testing, and operation and maintenance.5. The two fundamental types of evolutionary development are exploratory development and throwaway prototyping.

7、6. The evolutionary approach is often more effective than the waterfall approach in producing systems that meet the immediate needs of customers, but it is difficult to establish a(n) stable system architecture using this approach.7. CBSE is a(n) reuse-oriented approach to software development, whic

8、h relies on a large base of reusable software components and an integrating framework for these components.8. While CBSE can reduce the amount of software to be developed and the associated cost and risks, it cannot avoid requirements compromises which may lead to a system that does not meet the rea

9、l needs of users.II.Translate the following terms or phrases from English into Chinese and vice versa:1.system specification 系统规格说明2.unit testing 单位（或单元、部件）测试3.software life cycle 软件生命周期（或生存周期）4.system validation testing 系统验证测试5.evolutionary development process 演化开发过程6.linear model 线性模型7.program uni

10、t 程序单元8.throwaway prototype 抛弃式原型9.text formatting 正文格式编排，文本格式化10.system evolution 系统演变11.系统设计范例 system design paradigm12.需求分析与定义 requirements analysis and definition13.探索式编程方法 exploratory programming approach14.系统文件编制 system documentation15.瀑布模型 waterfall model16.系统集成 system integration17.商用现成软件 co

11、mmercial off-the-shelf (或COTS) software18.基于组件的软件工程 component-based software engineering (CBSE)19.软件维护工具 software maintenance tool20.软件复用 software reuseIV.Translate the following passage from English into Chinese:Software processes are complex and, like all intellectual and creative processes, rely

12、on people making decisions and judgments. Because of the need for judgment and creativity, attempts to automate software processes have met with limited success. Computer-aided software engineering (CASE) tools can support some process activities. However, there is no possibility, at least in the ne

13、xt few years, of more extensive automation where software takes over creative design from the engineers involved in the software process.One reason the effectiveness of CASE tools is limited is because of the immense diversity of software processes. There is no ideal process, and many organization h

14、ave developed their own approach to software development. Processes have evolved to exploit the capabilities of the people in an organization and the specific characteristics of the systems that are being developed. For some systems, a very structured development process is required while for others

15、 a flexible, agile process is likely to be more effective.软件过程比较复杂，而且像所有其他的智能和创造性过程一样，依靠人们作出决定和判断。由于需要判断和创造性，使软件过程自动化的尝试只取得了有限的成功。计算机辅助软件工程工具可支持软件过程的某些活动。然而，至少是在未来几年内，不可能实现更广泛的软件过程自动化，使软件能够接替参与软件过程的工程师来从事创造性设计。计算机辅助软件工程工具的有效性有限，原因之一是软件过程多种多样。不存在理想的过程，而且许多组织机构发展了自己的软件开发方法。软件过程不断演变，以利用组织机构中的人员的能力和开发中的

16、系统的具体特点。对于一些系统来说，需要的是一个高度结构化的开发过程，而对于另外一些系统来说，一个灵活敏捷的过程很可能更为有效。Unit Six: DatabaseUnit Six/Section AI.Fill in the blanks with the information given in the text:1. Data storage traditionally used individual, unrelated files, sometimes called flat files.2. According to the text, a DBMS is a combination

17、 of five components: hardware, software, data, users, and procedures. 3. As far as a DBMS is concerned, users can refer to both end users and application programs, and end users can refer to both database administrators and normal user.4. The three-level architecture for a DBMS discussed in the text

18、 consists of the internal, conceptual, and external levels.5. In the relational database models, data is organized in two-dimensional tables called relations.6. A distributed database can be classified either as a fragmented distributed database or as a replicated distributed database.7. While tryin

19、g to keep the advantages of the relational model, an object-oriented database allows applications to access structured data.8. An important step in the design of a database involves the building of a(n) entity-relationship model that defines the entities for which some information must be maintained

20、, the attributes of these entities, and the relationship between these entities.II.Translate the following terms or phrases from English into Chinese and vice versa:1.end user 最终用户，终端用户2.atomic operation 原子操作3.database administrator 数据库管理员4.relational database model 关系数据库模型5.local data 本地数据6.object-

21、oriented database 面向对象数据库7.database management system (DBMS) 数据库管理系统8.entity-relationship model (ERM) 实体关系模型9.distributed database 分布式数据库10.flat file 平面文件11.二维表 two-dimensional table12.数据属性 data attribute13.数据库对象 database object14.存储设备 storage device15.数据类型 data type16.数据插入与删除 data insertion and del

22、etion17.层次数据库模型 hierarchical database model18.数据库体系结构 database architecture19.关系数据库管理系统 relational database management system (RDBMS)20.全局控制总线 global control busIV.Translate the following passage from English into Chinese:In a relational database, the rows of a table represent records (collections o

23、f information about separate items) and the columns represent fields (particular attributes of a record). In conducting searches, a relational database matches information from a field in one table with information in a corresponding field of another table to produce a third table that combines requ

24、ested data from both tables. For example, if one table contains the fields EMPLOYEE-ID, LAST-NAME, FIRST-NAME, and HIRE-DATE, and another table contains the fields DEPT, EMPLOYEE-ID, and SALARY, a relational database can match the EMPLOYEE-ID fields in the two tables to find such information as the

25、names of all employees earning a certain salary or the departments of all employees hired after a certain date. In other words, a relational database uses matching values in two tables to relate information in one to information in the other. Microcomputer database products typically are relational

26、databases.在关系数据库中，表的行表示记录（关于不同项的信息集），列表示字段（一个记录的特定属性）。在进行搜索时，关系数据库将一个表中的一个字段的信息与另一个表的一个相应字段的信息进行匹配，以生成将来自这两个表的所要求数据结合起来的另一个表。例如，如果一个表包含EMPLOYEE-ID、LAST-NAME、FIRST-NAME和HIRE-DATE字段，另一个表包含DEPT、EMPLOYEE-ID和SALARY字段，关系数据库可匹配这两个表中的EMPLOYEE-ID字段，以找到特定的信息，如所有挣到一定薪水的雇员的姓名或所有在某个日期之后受雇的雇员所属的部门。换言之，关系数据库使用两个表中

27、的匹配值，将一个表中的信息与另一个表中的信息联系起来。微型计算机数据库产品一般是关系数据库。Unit Six/Section BI.Fill in the blanks with the information given in the text:1. The commit point is the point at which all the steps in a transaction have been recorded in the log of the DBMS.2. A large DBMS often contain a scheduler to coordinate time-

28、sharing among transactions in much the same way that a time-sharing operating system coordinates interweaving of processes.3. The items within a database that are currently being used by some transaction are marked with locks. There are two common types of locks: shared locks and exclusive locks.4.

29、With the wound-wait protocol, if an older transaction requires access to an item that is locked by a younger transaction is forced to release all of its data items, and its activities are rolled back.II.Translate the following terms or phrases from English into Chinese and vice versa:1.nonvolatile s

30、torage system 非易失性存储系统2.equipment malfunction 设备故障3.wound-wait protocol 受伤等待协议4.exclusive lock 排它锁，互斥（型）锁5.database integrity 数据库完整性6.共享锁 shared lock7.数据库实现 database implementation8.级联回滚 cascading rollback9.数据项 data item10.分时操作系统 time-sharing operating systemUnit Seven: Computer NetworksUnit Seven/S

31、ection AI.Fill in the blanks with the information given in the text:1. According to the geographical area covered, a computer network is often classified as either a LAN, a (n) MAN, or a WAN.2. A network can also be classified as either a (n) open network or a (n) closed network according to whether

32、 its internal operation is based on designs in the public domain or on innovations owned and controlled by a particular entity.3. A network can also be classified according to its topology. Among the most popular topologies are the bus topology, ring topology, and star topology.4. A popular protocol

33、 in networks based on the ring topology is the token ring protocol developed by IBM in the 1970s.5. In a (n) Ethernet system, the right to transmit messages is controlled by the protocol known as CSMA/CD.6. The client/server model for interprocess communication defines the basic roles played by the

34、processes as either a client or a server.7. The peer-to-peer model involves two processes communicating as equals and usually executing on a (n) temporary basis.8. Although it is often used, the term peer-to-peer network is not very appropriate.II.Translate the following terms or phrases from Englis

35、h into Chinese and vice versa: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

36、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 server20.广域网 wide area network (WAN)IV.Translate the following passa

37、ge from English into Chinese:A network, in computer science, is a group of computers and associated devices that are connected by communications facilities. A network can involve permanent connections, such as cables, or temporary connections made through telephone or other communications links. A n

38、etwork can be as small as a local area network consisting of a new computers, printers, and other devices, or it can consist of many small and large computers distributed over a vast geographic area. Small or large, a computer network exists to provide computer users with the means of communicating

39、and transferring information electronically. Some types of communication are simple user-to-user messages; others, of the type known as distributed processes, can involve several computers and the sharing of workloads or cooperative (合作的) efforts in performing a task.在计算机科学中，网络是指由通信设备连接在一起的一组计算机及其相关

40、设备。网络可采用电缆等永久性连接，或者采用通过电话或其他通信链路而实现的临时性连接。网络可以小到由少数计算机、打印机以及其他设备构成的局域网，也可以由分布在广大地理区域的许多小型与大型计算机组成。计算机网络无论大小，其存在的目的均在于为计算机用户提供以电子方式进行信息通信与传送的方法。有些类型的通信是简单的用户到用户消息；有些称为分布式过程，可能涉及数台计算机，以及在执行任务中分担工作量或进行协作。Unit Seven/Section BI.Fill in the blanks with the information given in the text:1. In the bus topol

41、ogy, a terminator should be installed at each end of the bus or main cable.2. As compared with the star topology, the extended star topology adds sub-central devices instead of connecting all devices to a central unit.3. The hierarchical topology, also referred to as the tree topology, is much like

42、the star topology, except that it doesnt use a (n) central node.4. A truly redundant network can be created with the mesh topology.II.Translate the following terms or phrases from English into Chinese and vice versa: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.

43、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 nodeUnit Eight: The InternetUnit Eight/Section AI.Fill in the blanks with the information given in the text:1. The Inte

44、rnet originated from research projects going back to the early 1960s.2. The establishment of domains on the Internet is overseen by a nonprofit corporation calledICANN或the Internet Corporation for Assigned Names and Numbers.3. A registered domain can be attached to the existing Internet by means of

45、a (n) router which is often referred to as the gateway of the domain.4. A user typically connects to the Internet in one of two ways: temporary/dial-up connections and permanent/dedicated connections.5. A (n) ISP或Internet service provider is a company that provides Internet access and other services

46、 to customers.6. An IP address is a 32-bit address made up of two parts: the network identifier and the host address, identifying the domain in which a computer resides and the particular computer within the domain respectively.7. IP address are traditionally written in dotted decimal notation.8. Fo

47、r ease of memorization, each domain is also assigned a unique mnemonic address known as a domain name.II.Translate the following terms or phrases from English into Chinese and vice versa: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5.network ident

48、ifier 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9.name 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

49、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 support IV.Translate the following passage from English into Chinese:The internet provides only the physical and logical infrastructure that

50、connects millions of computers together. Many believe that the World Wide Web (WWW, or simply the Web) provides the killer application (制胜法宝) for this global network. The Web is considered the content of the Internet, providing all sorts of information by using a rich set of tools that manage and li

51、nk text, graphics, sound, and video. Providing and viewing information on the Web is accomplished server applications and client applications.If youve already explored the Web, youll recognize the client-side application as the Web browser. A Web browser receives, interprets, and displays pages of i

52、nformation from the Web. The user can navigate within pages, jump to other pages by clicking hypertext links, and point to just about any page on the Web.因特网只是提供了将许许多多的计算机连接在一起的物理与逻辑基础结构。不少人认为，是万维网（WWW或简称the Web）为这个全球网络提供了“制胜法宝”。万维网被视为因特网的内容，它通过使用管理与链接文本、图形、声音和视频的一套丰富工具来提供各种信息。在万维网上提供和查看信息，是使用服务器应用程

53、序和客户应用程序完成的。如果你已经探索过万维网，你就会看出客户端应用程序就是万维网浏览器。万维网浏览器接收、解释和显示来自万维网的网页信息。用户可以在网页之内浏览，可以通过点击超文本链接跳到其他网页，也可以指向万维网上的几乎任何网页。Unit Eight/Section BI.Fill in the blanks with the information given in the text:1. For an outgoing message, the four layers of software involved in Internet communication work in the

54、order of the application layer, the transport layer, the network layer, and the link layer; for an incoming message, it is just the opposite.2. The transport layer converts long messages into packets compatible with the Internet before their transmission and reassembles them at the destination.3. Th

55、e packets related to a common message may follow different paths through the Internet.4. Only the link and network layers are involved at the intermediate stops during a packets journey to its final destination.II.Translate the following terms or phrases from English into Chinese and vice versa:1.in

56、coming 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 browserUnit Nine: Mobile and Cloud ComputingUnit Nine/Secti

57、on AI.Fill in the blanks with the information given in the text:1. The concept of cloud computing has evolved from cluster, grid, and utility computing.2. A public cloud is built over the Internet and can be accessed by any user who has paid for the service.3. A private cloud is built within the domain of a (n)intranet owned by a single organization.4. A (n) hybrid cloud is built with both public and private clouds.5.