计算机专业英语 第3版 课件 朱龙 Chapter6 Computer Network Technology（计算机网络技术）

阅读材料ReadingMaterial计算机专业英语chaptersix

ComputerNetworkTechnologyMissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?1.VarietiesofEthernet计算机专业英语FastEthernet100BASE-T:Atermforanyofthethreestandardsfor100

Mbit/sEthernetovertwistedpaircables,Including100BASE-TX,100BASE-T4and100BASE-T2.Asof2009,100BASE-TXhastotallydominatedthemarket,andisoftenconsideredtobesynonymouswith100BASE-Tininformalusage.100BASE-TX:100

Mbit/sEthernetoverCategory5cables(usingtwooutoffourpairs).Similarstar-shapedconfigurationto10BASE-T.100BASE-T4:100

Mbit/sEthernetoverCategory3cables(asusedfor10BASE-Tinstallations).Usesallfourpairsinthecable,andislimitedtohalf-duplex.Nowobsolete,asCategory5cablesarethenorm.100BASE-T2:100

Mbit/sEthernetoverCategory3cables.Usingonlytwopairs,andsupportingfull-duplex,itisfunctionallyequivalentto100BASE-TX,butsupportsoldcable.Noproductssupportingthisstandardwasevermanufactured.100BASE-FX:100

Mbit/sEthernetoverfiber.MissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?1.VarietiesofEthernet计算机专业英语GigabitEthernet1000BASE-T:1

Gbit/soverunshieldedtwistedpaircoppercabling(atleastCategory5cables,withCategory5estronglyrecommended).1000BASE-SX:1

Gbit/sovershortrangemulti-modefiber.1000BASE-LX:1

Gbit/soverlongrangesingle-modefiber.1000BASE-CX:Ashort-haulsolution(upto25

m)forrunning1

Gbit/sEthernetoverspecialcoppercable.Predates1000BASE-T,andnowobsolete.

10-gigabitEthernetThe10gigabitEthernetfamilyofstandardsencompassesmediatypesforsingle-modefibre(longhaul),multi-modefibre(upto300

m),copperbackplane(upto1

m)andcoppertwistedpair(upto100

m).ItwasfirststandardisedasIEEEStd802.3ae-2002,butisnowincludedinIEEEStd802.3-2008.MissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?1.VarietiesofEthernet计算机专业英语10GBASE-SR:designedtosupportshortdistancesoverdeployedmulti-modefibercabling,ithasarangeofbetween26

mand82

mdependingoncabletype.Italsosupports300

moperationoveranew2000

MHz·kmmulti-modefiber.10GBASE-LX4:useswavelengthdivisionmultiplexingtosupportrangesofbetween240

mand300

moverdeployedmulti-modecabling.Alsosupports10

kmoversingle-modefiber.10GBASE-LRand10GBASE-ER:thesestandardssupport10

kmand40

kmrespectivelyoversingle-modefiber.10GBASE-SW,10GBASE-LWand10GBASE-EW.ThesevarietiesusetheWANPHY,designedtointeroperatewithOC-192/STM-64SONET/SDHequipment.Theycorrespondatthephysicallayerto10GBASE-SR,10GBASE-LRand10GBASE-ERrespectively,MissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?1.VarietiesofEthernet计算机专业英语andhenceusethesametypesoffiberandsupportthesamedistances.(ThereisnoWANPHYstandardcorrespondingto10GBASE-LX4.)10GBASE-T:designedtosupportcoppertwistedpairandwasspecifiedbytheIEEEStd802.3an-2006whichhasbeenincorporatedintotheIEEEStd802.3-2008.MissLi:AsalesgirlinComputerTownPreviously,datacommunicationwasbasedontheideaofcircuitswitching,asintheoldtypicaltelephonecircuit,whereadedicatedcircuitistiedupforthedurationofthecallandcommunicationisonlypossiblewiththesinglepartyontheotherendofthecircuit.Mr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?2.ARPANET计算机专业英语TheARPANET(AdvancedResearchProjectsAgencyNetwork),createdbytheARPAoftheUnitedStatesDepartmentofDefenseduringtheColdWar,wastheworld’sfirstoperationalpacketswitchingnetwork,andthepredecessoroftheglobalInternet.Packetswitching,nowthedominantbasisforbothdataandvoicecommunicationworldwide,wasanewandimportantconceptindatacommunication.Previously,datacommunicationwasbasedontheideaofcircuitswitching,asintheoldtypicaltelephonecircuit,whereadedicatedcircuitistiedupforthedurationofthecallandcommunicationisonlypossiblewiththesinglepartyontheotherendofthecircuit.MissLi:AsalesgirlinComputerTownPreviously,datacommunicationwasbasedontheideaofcircuitswitching,asintheoldtypicaltelephonecircuit,whereadedicatedcircuitistiedupforthedurationofthecallandcommunicationisonlypossiblewiththesinglepartyontheotherendofthecircuit.Mr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?2.ARPANET计算机专业英语Withpacketswitching,asystemcoulduseonecommunicationlinktocommunicatewithmorethanonemachinebydisassemblingdataintodatagrams,thengathertheseaspackets.Notonlycouldthelinkbeshared(muchasasinglepostboxcanbeusedtopostletterstodifferentdestinations),buteachpacketcouldberoutedindependentlyofotherpackets.AformofpacketswitchingdesignedbyLincolnLaboratoryscientistLawrenceRobertsunderlaythedesignofARPANET.BackgroundofARPANETTheearliestideasofacomputernetworkintendedtoallowgeneralcommunicationbetweenusersofvariouscomputerswereformulatedbyJ.C.R.LickliderofBolt,BeranekandNewman(BBN)inAugust1962,inaseriesofmemosdiscussinghis“IntergalacticComputerNetwork”concept.TheseideascontainedalmosteverythingthattheInternetistoday.MissLi:AsalesgirlinComputerTownPreviously,datacommunicationwasbasedontheideaofcircuitswitching,asintheoldtypicaltelephonecircuit,whereadedicatedcircuitistiedupforthedurationofthecallandcommunicationisonlypossiblewiththesinglepartyontheotherendofthecircuit.Mr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?2.ARPANET计算机专业英语InOctober1963,LickliderwasappointedheadoftheBehavioralSciencesandCommandandControlprogramsatARPA(asitwasthencalled),theUnitedStatesDepartmentofDefenseAdvancedResearchProjectsAgency.HethenconvincedIvanSutherlandandBobTaylorthatthiswasaveryimportantconcept,althoughheleftARPANETbeforeanyactualworkonhisvisionwasperformed.ARPAandTaylorcontinuedtobeinterestedincreatingacomputercommunicationnetwork,inparttoallowARPA-sponsoredresearchersinvariouslocationstousevariouscomputerswhichARPAwasproviding,andinparttomakenewsoftwareandotherresultswidelyavailablequickly.Taylorhadthreedifferentterminalsinhisoffice,connectedtothreedifferentcomputerswhichARPAwasfunding:onefortheSDCQ-32inSantaMonica,oneforProjectGenieattheUniversityofCalifornia,Berkeley,andoneforMulticsatMIT.Taylorlaterrecalled:MissLi:AsalesgirlinComputerTownPreviously,datacommunicationwasbasedontheideaofcircuitswitching,asintheoldtypicaltelephonecircuit,whereadedicatedcircuitistiedupforthedurationofthecallandcommunicationisonlypossiblewiththesinglepartyontheotherendofthecircuit.Mr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?2.ARPANET计算机专业英语“Foreachofthesethreeterminals,Ihadthreedifferentsetsofusercommands.SoifIwastalkingonlinewithsomeoneatS.D.C.andIwantedtotalktosomeoneIknewatBerkeleyorM.I.T.aboutthis,IhadtogetupfromtheS.D.C.terminal,gooverandlogintotheotherterminalandgetintouchwiththem.Isaid,oh,man,it’sobviouswhattodo:Ifyouhavethesethreeterminals,thereoughttobeoneterminalthatgoesanywhereyouwanttogo.ThatideaistheARPANET.”Somewhatcontemporaneously,anumberofpeoplehad(mostlyindependently)workedoutvariousaspectsofwhatlaterbecameknownas“packetswitching”,withthefirstpublicdemonstrationbeingmadebytheUK’sNationalPhysicalLaboratory(NPL)on5August5,1968.ThepeoplewhocreatedtheARPANETwouldeventuallydrawonallthesedifferentsources.MissLi:AsalesgirlinComputerTownPreviously,datacommunicationwasbasedontheideaofcircuitswitching,asintheoldtypicaltelephonecircuit,whereadedicatedcircuitistiedupforthedurationofthecallandcommunicationisonlypossiblewiththesinglepartyontheotherendofthecircuit.Mr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?3.Hotmail计算机专业英语InDecember1995,SabeerBhatiaandJackSmithvisitedtheInternetventurecapitalistDraperFisherJurvetsonandproposeddevelopingafreeWeb-basedE-mailsystem.TheideawastogiveafreeE-mailaccounttoanyonewhowantedone,andtomaketheaccountsaccessiblefromtheWeb.WithWeb-basedE-mail,anyonewithaccesstotheWeb——say,fromaschoolorcommunitylibrary——couldreadandsendE-mails.Furthermore,web-basedE-mailwouldoffergreatmobilitytoitssubscribers.Inexchangefor15percentofthecompany,DraperFisherJurvetsonfinancedBhatiaandSmith,whoformedacompanycalledHotmail.Withthreefull-timepeopleand12～14part-timepeoplewhoworkedforstockoptions,theywereabletodevelopandlaunchtheserviceinJuly1996.Withinamonthafterlaunchtheyhad100

000subscribers.Thenumberofsubscriberscontinuedtogrowrapidly,withalloftheirsubscribersbeingexposedtoadvertisingbannerswhilereadingtheirE-mail.MissLi:AsalesgirlinComputerTownPreviously,datacommunicationwasbasedontheideaofcircuitswitching,asintheoldtypicaltelephonecircuit,whereadedicatedcircuitistiedupforthedurationofthecallandcommunicationisonlypossiblewiththesinglepartyontheotherendofthecircuit.Mr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?3.Hotmail计算机专业英语withalloftheirsubscribersbeingexposedtoadvertisingbannerswhilereadingtheirE-mail.InDecember1997,lessthan18monthsafterlaunchingtheservice,Hotmailhadover12millionsubscribersandwasacquiredbyMicrosoft,reportedlyfor$400milliondollars.

ThesuccessofHotmailisoftenattributedtoits“first-moveradvantage”andtotheinherent“viralmarketing”ofE-mail.Hotmailhadafirst-moveradvantagebecauseitwasthefirstcompanytoofferWeb-basedE-mail.Othercompanies,ofcourse,copiedHotmail’sidea,butHotmailhadasix-monthleadonthem.Thecovetedfirst-moveradvantageisobtainedbyhavinganoriginalidea,andthendevelopingquicklyandsecretly.Aserviceoraproductissaidtohaveviralmarketingifitmarketsitself.MissLi:AsalesgirlinComputerTownPreviously,datacommunicationwasbasedontheideaofcircuitswitching,asintheoldtypicaltelephonecircuit,whereadedicatedcircuitistiedupforthedurationofthecallandcommunicationisonlypossiblewiththesinglepartyontheotherendofthecircuit.Mr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?3.Hotmail计算机专业英语E-mailisaclassicexampleofaservicewithviralmarketing—thesendersendsamessagetooneormorerecipients,andthenalltherecipientsbecomeawareoftheservice.Hotmaildemonstratedthatthecombinationoffirst-moveradvantageandviralmarketingcanproduceakillerapplication.Perhapssomeofthestudentsreadingthisbookwillbeamongthenewentrepreneurswhoconceiveanddevelopfirst-moverInternetserviceswithinherentviralmarketing.感谢观看Ｔｈhankyouforwatching计算机专业英语练习Exercises计算机专业英语chaptersixComputerNetworkTechnologyMissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?1．MatchtheexplanationsinColumnBwithwordsandexpressionsinColumnA.计算机专业英语搭配下列每组中意义相同的词或短语AB交换机IP路由器IDPS组件Switch传输控制协议Router互联网协议Component万维网TCP入侵检测和防御系统WWWAB超文本传输控制协议NetworkSafety电子邮件Firewall文件传输协议E-mail防火墙IDS入侵检测系统FTP网络安全OSI开放系统互联HTTPMissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?2.Choosetheproperwordstofillintheblanks.计算机专业英语选词填空ALANisusedforcommunicationsinasmallcommunityinwhichresources,suchas(),software,andservers,areshared.EachdeviceconnectedtoaLANhasaunique().TwoormoreLANsofthesametypecanalsobeconnectedto()dataframesamongmultipleusersofotherlocalareanetworks.InLANs,()areadditionalheadersappendedforlocalrouting.Thesenew-lookingpacketsareknownas().Packets，address，frames，printers，forwardWordstobechosenfrom:（可选词）MissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?3．TranslatethefollowingEnglishSentencesintoChinese.计算机专业英语将下面英语句子翻译为中文（1）TheInternetisaglobalsystemofinterconnectedcomputernetworksthatusethestandardInternetProtocolSuite(TCP/IP)toservebillionsofusersworldwide.___________________________________________________（2）Aswithmostapplication-layerprotocols,SMTPhastwosides:Aclientside,whichexecutesonthesender’smailserver,andaserverside,whichexecutesontherecipient’smailserver.

__________________________________________________（3）Inthestartopology,allusersaredirectlyconnectedtoacentraluserthroughtwounidirectionallinks:oneforuplinkandtheotherfordownlink.

__________________________________________________（4）Acomputernetworkisagroupofcomputersthatareconnectedtoeachotherforthepurposeofcommunication.__________________________________________________MissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?3．TranslatethefollowingEnglishSentencesintoChinese.计算机专业英语将下面英语句子翻译为中文

（5）WANsareusedtoconnectLANsandothertypesofnetworkstogether,sothatusersandcomputersinonelocationcancommunicatewithusersandcomputersinotherlocations.__________________________________________________

Let’sgo!感谢观看Ｔｈhankyouforwatching计算机专业英语情境对话SituationDialogue计算机专业英语chaptersix

ComputerNetworkTechnologyMissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?Shoppingonline计算机专业英语网购XiaoMingandLiLiangaregoodfriends.LiLiangisacomputerexpertwhooftenbuysthingsonline.XiaoMing:Moreandmorepeoplelikeon-lineshopping.LiLiang:Yes,thepriceisloweronline.XiaoMing:Isawadigitalcameraonline.LiLiang:Areyoureadytodoshoppingonline?XiaoMing:Yes,butIdonotknowhowtodoit,canyoushowme?小明和李亮是好朋友。李亮是计算机高手，经常在网上买东西。小明：现在喜欢网上购物的人越来越多了。李亮：是呀，网上的东西价格比较便宜。小明：我也在网上看中一款数码相机。李亮：你也准备网上购物？小明：是的，但是我不知道怎么做，你能教教我吗？MissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?Shoppingonline计算机专业英语网购LiLiang:OK.Therearemanyfishingsitesonthenetwork,sofirstly，selectingthesitewhichyoucantrustisveryimportant.XiaoMing:Whatsites?LiLiang:Tobuyadigitalcamera,thereareJingdong,Newegg,Taobao,eBay,andsoon.XiaoMing:Canitbetradedafterchoosingtherightproducts?李亮：好的。网络上有很多钓鱼网站，选择可以信任的网站是非常重要的。

小明：有哪些网站呢？李亮：买数码相机的话，有京东、新蛋、淘宝、易趣等。小明：选好产品后就可以进行交易了？MissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?Shoppingonline计算机专业英语网购LiLiang:Yes,selectadigitalcamera,pay,receivedigitalcamera.It’ssosimple.XiaoMing:Nowondereveryonelikesonlineshopping.LiLiang:Althoughsimple,manytechniquesareused.Takethenetworkside,thereareHTTP,DNS,networkdeviceconfiguration,thedevelopmentofstandardsandprotocols,andsoon.李亮：是的，选数码相机、付钱，收到数码相机，就是这么简单。小明：难怪大家都喜欢网上购物。李亮：虽然简单，但用到的技术很多。就拿网络方面来说，主要有HTTP、DNS、网络设备配置、标准和协议的制定等。MissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?Shoppingonline计算机专业英语网购XiaoMing:Itsoundsverycomplicated.LiLiang:Ofcourse,onlinechattingandwatchingmoviesareusedmanynetworkingtechnologies.XiaoMing:NowIturnthecomputeron,HowdoyouthinkthedigitalcameraIchosed?LiLiang:OK.小明：听起来很复杂。李亮：当然，网上聊天、看电影，这些都用到很多的网络技术。小明：我把计算机打开，你看我选的数码相机怎么样？李亮：好的。感谢观看Ｔｈhankyouforwatching计算机专业英语对照阅读ReadingandComparing计算机专业英语chaptersix

ComputerNetworkTechnologyMissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?WhatareComputerViruses?计算机专业英语什么是计算机病毒？Computervirusesareprogramswrittenby“mean”people.Thesevirusprogramsareplacedintoacommonlyusedprogramsothatprogramwillruntheattachedvirusprogramasitboots,therefore,itissaidthatthevirus“infects”theexecutablefileorprogram.计算机病毒是“有不良企图”的人撰写的程序。这些病毒程序被放置在一个常用的程序中，该程序启动后就会运行附加病毒程序，因此，我们说该病毒“感染”了可执行文件或程序。MissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?WhatareComputerViruses?计算机专业英语什么是计算机病毒？ExecutablefilesincludeMacintosh“systemfiles”(suchassystemextensions,INITsandcontrolpanels)andapplicationprograms(suchaswordprocessingprogramsandspreadsheetprograms).VirusesworkthesamewaysinWindowsorDOSmachinesbyinfectingziporexefiles.可执行文件包括Macintosh“系统文件”（如系统扩展、初始化和控制面板）和应用程序（如文字处理程序和电子表格程序）。病毒在Windows或DOS机器上感染zip或exe文件也采用相同的工作方式。MissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?WhatareComputerViruses?计算机专业英语什么是计算机病毒？Avirusisinactiveuntilyouexecuteaninfectedprogramorapplicationorstartyourcomputerfromadiskthathasinfectedsystemfiles.Onceavirusisactive,itloadsintoyourcomputer’smemoryandmaysaveitselftoyourharddriveorcopiesitselftoapplicationsorsystemfilesondisksyouuse.病毒处于非活动状态，直到你执行受感染的应用程序或从磁盘启动已经感染的计算机系统文件才被激活。病毒一旦激活，它将加载到你的计算机内存中，并可能保存到你的硬盘驱动器或将自身复制到磁盘上的应用程序或系统文件中。MissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?WhatareComputerViruses?计算机专业英语什么是计算机病毒？Somevirusesareprogrammedspecificallytodamagethedataonyourcomputerbycorruptingprograms,deletingfiles,orevenerasingyourentireharddrive.Manyvirusesdonothingmorethandisplayamessageormakesounds/verbalcommentsatacertaintimeoraprogrammingeventafterreplicatingthemselvestobepickedupbyotherusersonewayoranother.一些病毒是为了损害你的计算机上的数据专门设计的程序，它们破坏程序、删除文件，甚至清除你的整个硬盘驱动器。许多病毒只是显示一条消息，或使声音/口头禅注释自我复制至其他用户，自我复制是在某一特定的时间或者程序事件后执行的。MissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?WhatareComputerViruses?计算机专业英语什么是计算机病毒？Othervirusesmakeyourcomputer’ssystembehaveerraticallyorcrashfrequently.Sadlymanypeoplewhohaveproblemsorfrequentcrashesusingtheircomputersdonotrealizethattheyhaveavirusandlivewiththeinconveniences.其他病毒使计算机系统的行为不正常或频繁崩溃，可悲的是很多使用有问题计算机的用户没有意识到，是病毒给他们带来了不便。MissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?WhatVirusesDon’tDo!计算机专业英语什么是病毒做不了的！Computervirusescannotinfectwriteprotecteddisksorinfectwrittendocuments.Virusesdonotinfectcompressedfiles,unlessthefilewasinfectedpriortothecompression.Compressedfilesareprogramsorfileswithitscommoncharacters,etc.removedtotakeuplessspaceonadisk.Virusesdonotinfectcomputerhardware,suchasmonitorsorcomputerchips;theyonlyinfectsoftware.计算机病毒无法感染写保护的磁盘或书面文件。病毒不能感染压缩的文件，除非文件是在被压缩之前感染了。压缩文件程序具有的共同特征是文件占用的磁盘空间较少。病毒不感染计算机硬件，如显示器或计算机芯片，它们只感染软件。MissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?WhatVirusesDon’tDo!计算机专业英语什么是病毒做不了的！Inaddition,MacintoshvirusesdonotinfectDOS/Windowcomputersoftwareandviceversa.Forexample,theMelissavirusincidentoflate1998andtheILOVEYOUvirusof2000workedonlyonWindowbasedmachinesandcouldnotoperateonMacintoshcomputers.此外，Macintosh病毒不感染DOS/窗口计算机软件，反之亦然。例如，1998年底的Melissa病毒和2000年的ILOVEYOU病毒只能在基于窗口工作的机器上运行，不能在Macintosh计算机上运行。MissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?WhatVirusesDon’tDo!计算机专业英语什么是病毒做不了的！Onefurthernoteisvirusesdonotnecessarilyletyouknowtheyarepresentinyourmachine,evenafterbeingdestructive.Ifyourcomputerisnotoperatingproperly,itisagoodpracticetocheckforviruseswithacurrent“viruschecking”program.还有一项值得注意的是，病毒并不一定让你知道它们目前是在你的机器上，虽然它们之后会有破坏性。如果你的计算机没有正常运行，用流行的查毒软件检查病毒是一个很好的做法。MissLi:AsalesgirlinComputerTownMr.Zhang:AcomputerconsumerwhoknowslittleaboutcomputerLi:CanIhelpyou,Sir?Zhang:Yes.I’dliketobuyacomputer,butIknowlittleaboutit.Li:Doyoulikeabrandmachineoracompatiblemachine?HowdoVirusesSpread?计算机专业英语病毒如何传播？Virusesbegintoworkandspreadwhenyoustartuptheprogramorapplicationinwhichthevirusispresent.Forexample,awordprocessingprogramthatcontainsaviruswillplacethevirusinmemoryeverytimethewordprocessingprogramisrun.当你启动存在病毒的应用或程序时，病毒开始运行并传播。例如，包含一个病毒文字处理程序将会把该病毒放置在内存中，随着每次文字处理程序的运行而传播病毒。MissLi: