国家开放大学电大本科《计算机网络》期末试题及答案（试卷号：1255）

2021-2022国家开放大学电大本科《计算机网络》期末试题及答案（试卷号：1255） 盗传必究 一、选择题（每题2分，共20分） 1．将数字信号调制成模拟音频信号后再传输的方式称为( )。

A．基带传输 B．宽带传输 C．频带传输 D．同步传输 2．数据通信按照信号传送方向和时间的关系，信道的通信方式可以分为三种：单工、半双工和( )。

A．数字传输 B．全双工 C．信道传输 D．模拟传输 3．( )参考模型层次结构中，没有表示层和会话层。

A．OSI B．TCP/IP C．DNS D．ISO 4．UDP是( )层的一个协议。

A．数据链路层 B．网络层 C．传输层 D．应用层 5．数据链路层中的传送单位是( )。

A．比特位 B．字节 C．帧 D．数据报文 6．IEEE802局域网参考模型主要包含( )两层功能。

A.物理层和介质访问控制层 B．物理层和数据链路层 C．物理层和网络层 D．数据链路层和网络层 7．VLAN是一种( )。

A．无线局域网 B．一种局域网接入设备 C．路由器 D．虚拟局域网 8．计算机网络系统是由( )和资源子网组成的。

A．安全子网 B．交换子网 C．通信子网 D．局域网 9．路由器是一种在( )层上实现多个网络之间互连的设备。

A.物理层 B．传输层 C．网络层 D．数据链路层 10.要让一台计算机上网，首先要接人，然后需要有一个IP地址，其IP地址可以通过( )协议由服务器分配得到。

A．HTTP B．DNS C．ARP D．DHCP 二、是非题（请在括号内，正确的划√，错误的划×。每题1分，共10分） 11．IP网，即我们日常生活中常用的电话网，是一种用于全球语音通信的电路交换网络，是目前世界上最大的网络。( × ) 12．数据交换技术的主要功能是实现两个用户数据的交换。( × ) 13.PPP协议为数据链路层协议。( √ ) 14.IPV6地址采用128位二进制结构。( √ ) 15.计算机病毒是指编制或者在计算机程序中插入的破坏计算机功能或者破坏数据，影响计算机使用并且能够自我复制的一组计算机指令或者程序代码。( √ ) 16.从网络的作用范围进行分类，计算机网络可以分为广域网、局域网、校园网。( × ) 17.在TCP/IP协议族中实现从IP地址到物理地址的映射的是RARP协议。( × ) 18.计算机网络按拓扑结构可分为：电话网络、总线型网络、树型网络、环型网络和网状型网络五种。( × ) 19．物理层负责建立相邻结点之间的数据链路，提供节点间可靠数据传输。( × ) 20．复用技术主要是用来提高信道的利用率，通常使用数据压缩技术来实现。( × ) 三、填空题（每空2分，共20分） 21．PPP协议为基于点到点连接的多协议自寻址数据包的传输提供了一个标准方法。

22.计算机网络就是利用通信设备和线路将地理位置上不同的、功能独立的多个计算机系统互连起来，以功能完善的网络软件实现网络中资源共享和信息传递的系统。

23.在计算机网络体系中，对等实体之间交换数据或通信时所必须遵守的规则和标准的集合称为协议。

24.信息是客观事物的属性和相互联系特性的表现。

25．计算机网络功能概括为以下几个方面：资源共享、数据通信、集中管理、安全功能等。

26．计算机病毒-是指编制或者在计算机程序中插入的破坏计算机功能或者破坏数据，影响计算机使用并且能够自我复制的一组计算机指令或者程序代码。

四、简答题（每题15分，共30分） 27.什么是单工通信、半双工通信和全双工通信？各有何特点？ 答：数据通信按照信号传送方向和时间的关系，信道的通信方式可以分为三种：单工、半双工和全双工。

单工通信：在单工通信方式中，信号只能向一个方向传输。例如：无线广播电台的广播、电视播放。（5分） 半双工通信：在半双工通信方式中，信号可以双向传送，但必须交替进行，在任一时刻只能向一个方向传送。例如：对讲机。（5分） 全双工通信：在全双工通信方式中，信号可以同时双向传送数据。例如：以太网通信。（5分） 28.HTTP协议的主要特点有哪些 答：(1)支持客户／服务器模式。（3分） (2)简单快速：客户向服务器请求服务时，只需传送请求方法和路径。（3分） (3)灵活：HTTP允许传输任意类型的数据对象。（3分） (4)无连接：无连接的含义是限制每次连接只处理一个请求。（3分） (5)无状态：无状态是指协议对于事务处理没有记忆能力。（3分） 五、论述题（共20分） 29.按照网络服务方式的不同可以将网络分为三类，C/S、B/S和P2P，请解释它们的含义和内容？试 答：计算机网络按网络的服务方式分类可以分为：客户机／服务器模式、浏览器／服务器模式和对等网三种。（2分） (1)客户机／服务器(client/server C/S)模式：在客户机／服务器(C/S)模式中，服务器指的是在网络上可以提供服务的任何程序（计算机），客户指的是向服务器发起请求并等待响应的程序（计算机）。服务器一般以并发服务器的方式随系统启动而启动，当无请求时，服务器处于等待状态；

当请求到达时，服务器为其产生一个子进程，处理这个请求并做出响应。（6分） (2)浏览器／服务器(B/S)模式是因特网上使用的模式。这种模式最主要的特点是与软硬件平台无关性，把应用逻辑和业务处理规则放在服务器一侧。（6分） (3)对等网(Peer to Peer)是指系统内每台计算机的“地位”是平等的，允许每台计算机共享其它计算机内部的信息资源和硬件资源；

对等网内的计算机一般类型相同，甚至操作系统也相同。（6分）

探究到了很深层的问题！

试卷代号：1162

中央广播电视大学2009-2010学年度第一学期“开放本科”期末考试英语Ⅱ(2) 试题

2010年1月

第一部分交际用语（共计10分，每小题2分）

1-5小题：阅读下面的小对话，从A、B、C、D四个选项中选出一个能填入空白处的最佳选项，并在答题纸上写出所选的字母符号。

1.Can you help me clear up the me?-------------------- A.Tell me who made it B.No trouble at allC.Yes, that\\"ll be all right D.No problem 3.Is it going to be warm next week?------------------- A.Yes, it is B.I don\\"t believe it C.No, it hasn\\"t D.It changes all the time 5.15小题：阅读下面的句子，从A、B、C、D四个选项中选出一个能填入空白处的最佳选项，并在答题纸上写出所选的字母符号。

6.Unfortunately the poor girl can\\"t do anything but ------- .all her belongings at alow price.A.to sell B.sellingC.sell D.sold 7.They were asked to avoid _ any water which had not been boiled. A.drinking B.to drink C.having D.not to be drunk 8.John was bored, _ he left his life in England.. A.in addition B.so C.however D.furthermore 9.She is very careful.She _ very few mistakes in her work. A.does B.takesC.makes D.gets 10.The workers are busy _ models for the exhibition. A.to make B.with makingC.being making D.making 11.--------- you change your mind, I won\\"t be able to help you. A.When B.UnleC.While D.So 12.We are going to have our office _ to make room for a new engineer. A.to rearrange B.rearrange C.rearranged D.rearranging 13.Since this road is wet and slippery this morning, it _--------- last night. A.must rajn B.was raining C.may be raining D.must have rained 14.Do you think Tommy is--------- the truth? A.sayingB.tellingC.speaking D.talking 15.John fell asleep _

he was listening to the music.A.while B.before C.after D.as soon as 第三部分完形填空（每题2分，共20分）

16carrots can be made to taste of chocolate andapples can be made 18 .Some food that appears the same has been 19 improved, forexample, fish can be made to grow faster.Should we \\"be pleased or worried? Will newtechnology bring benefits, or is it about to g0 20 control? Genetically engineered foods are produced by taking genetic material from one speciesand transferring it 21 another.For example, an 6antifreeze\\" gene which appearsnaturally in Arctic fish has been introduced into tomatoes and strawberries 22 they don\\"t freezein cold weather; a human gene has been introduced into pigs to make them 23 morequickly. Some claim great advantages.They point out that crops can be made stronger and moredisease resistant, _ 24 _ pesticides can be reduced.They also maintain that food can bemade more nutritious

or that the fat content can 25 to make it healthier.16.A.are B.were C.is D.be 17.A.such that B.such as C.so that D.so as 18.A.more red B.much red C.redder D.reder 19.A.scientifically B.science C.scientific D.scientifical 20.A.under B.into C.out D.out of 21.A.for B.to C.out D.into 22.A.such that B.in order to C.so that D.so as to 23.A.grow B.to grow C.growing D.grown 24.A.because B.cause C.result D.so 25.A.be reducing B.be reduced C.reduced D.reducing 第四部分 阅读理解（共计30分，每小题2分） 26I gue you can put up with a mattre on the floor! 26.This paage is a letter of . A.an informal invitation B.a formal invitation C.thanks D.complaint 27.When Charles writes, "I\\"m sorry about the lack of warning", he means that he is sorry that _ . A: he did not give Bob a warning when Bob was unce in danger B.he is short of money, so he is not able to help Bob C.he should have given Bob a warning when he is in difficulty D.he is not able to write this letter to Bob earlier 28.Charles and his wife decided to hold the house-warming party9 mainly because A.they decided to have a rest after being busy moving to the new house B.they still had a little money left to afford the party C.the new motorway was open D.they wanted to meet their friends very much 29.From the letter we know that the new house that Charles moved in is B.two hours away from downtown A.very big x C.in a new housing estate D.easy to find in the map 30.In the sentence "Barbara and l hope that you can make it...", the phrase "make it" is used to say that Bob can A.manage to attend their party B.find their new house in two hours C.do the trip from Bedford to Flinders D.put up with a mattre on the floor 短文理解2 Cash of all kinds, the French franc, the German mark, and the Italian lira, is bound to disappear physically.The paper notes and gold coins may soon become curious collections of the pre-electronic age.Digital money can replace every use of cash money.It is true that electronic money has been around for decades.Each week billions of institutional dollars flow through the Interbank Payment System through telephone wires and satellite links.But in the 21st century, entirely new forms of digital moneywill become the means

of most personal financial trade.What a great change this will be! Digital credit cards, smart cards, electronic wallets and electronic checks will change our way of life in the 21st century.They are efficient and easy to use.Customers will not take money with them when they go shopping.They will pay their\\"bills from a smart cell phone or they will buy their coffee by using a digital credit card.How convenient it will be! And how easily people will do their shopping in such a way! With so many changes these days, the Internet will help speed up the end of cash.In Europe, some banks have been offering people electronic cash since late last year.Customers can withdraw money from their accounts through the bank\\"s website and store their incomes on their home PCs.As the electronic cash is downloaded, the customers\\" bank accounts are recorded.Since customers can use electronic cash to buy things on the Internet, electronic cash will transform the Internet into a global marketplace for everything.It is going to have a very big impact on our lives.The low cost of computer and communications has created a worldwide medium not just for finance, but also for many other things in our life.The Age of Internet has brought e-businees to our life, which perhaps will form the backbone of our economy.Mom and Pop can go global40小题：阅读下列短文，并根据短文内容判断其后的句子是否正确(T)、错误(F),还是文字中没有涉及相关信息(NG)。 阅读理解3 CETACEANS: FACT FILE There are over 80 species of whales, dolphins and porpoises, known collectively as "cetaceans", throughout the world.They come in all shapes and sizes.Here are some facts and figures about these incredible animals. 1.Largest The blue whale is the heaviest and Jongest animal on Earth.The average adult length is 25m for males and 26.2m for females, with body weights of 90-120 tonnes. 2.Smallest Hector\\"s dolphin is the world\\"s shortest cetacean.They may be only l.2m long when fully grown. 3.Largest Appetite A blue whale eats up t0 4 tonnes of krill daily.This is equivalent to eating a fully grown African elephant every day. 4.Deepest Dive The sperm whale is believed to dive deeper than any other cetacean.They have been known to

dive as deep as 2000m. 5.Longest Lived One bowhead whale is reported to have been 130 years old when it died.6.Heaviest Brain The sperm whale has the world\\"s heaviest brain which can weigh up t0 9.2kg.This compares with the average l.4kg for the brain of an adult human. 7.Most Endangered The baiji dolphin, or Chinese river dolphin, is the rarest dolphin in the world and isreported to be endangered.It lives in the Yangtze River in China.Conservation measures arebeing taken by the Chinese to save it..Questions 36-40: 36.Hector\\"s dolphin is the smallest fish in the world. 37.Blue whales eat as much as an African elephant does every day.38.Some whales can live for as long as 130 years. 39.Whales are cleverer than humans. 40.The brain of a sperm whale can be over 6 times heavier than a human one.第五部分书面表达（20分）

Directions: For this part, you are allowed thirty minutes to write an email to口businepartner named Robert in London about your trip next week.You should write at least 80words and base your email on the Chinese outline below: 1．接受邀请下星期到英国观光旅游。2．希望对方能到机场接你。 3．告诉对方你抵达的日期和航班号等。

试卷代号：1 1 62 中央广播电视大学2009-2010学年度第一学期“开放本科”期末考试

英语Ⅱ(2) 试题答案及评分标准

第一部分交际用语（共计10分，每小题2分）

1．B 2．D 3．D 4．A 5．C 第二部分词汇与结构（共计20分．每小题2分）

6．C 7．A 8．B 9．C 10．D11．B 12．C13．D 14．B 15．A第三部分完形填空（共计20分，每小题2分）

16．A17.B 18．C 19．A 20．D21．B 22．C 23．A 24．D 25．B第四部分 阅读理解（共计30分，每小题2分） 26．A27.D 28．B 29．C 30.A31．C 32．A 33．D 34．B 35．C36.F 37.F 38.T 39.NG 40.T第五部分 写作（共计20分）

Sample Dear Robert, I\\"m very pleased to accept the kind invitation you extended in your last email.I\\"mplanning to spend my holiday in Britain next week.Since this is my first visit to your country, I hope you will be able to meet me at the airport.My flight details-the plane leaves Beijing at 12:30 next Thursday and arrives in London at 14:30 (local time).The flight number is CA1347. Thank you and looking forward to meeting you in London.Linlin

启发了我！

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