計基課本課后習(xí)題

Chapter1ComputersandDigitalBasics1A“AllThingsDigital”Dataprocessingwasthecomputingtechnologybehindthefirstphaseofthedigitalrevolution.Localsoftwarereferstoanysoftwarethatisinstalledonacomputer’sharddrive.Acomputernetworkisagroupofcomputerslinkedtogethertosharedataandresources.Theprocessofconvertingtext,numbers,sound,photos,orvideointodatathatcanbeprocessedbyacomputeriscalleddigitization.Cloudcomputingprovidesaccesstoinformation,applications,communications,andstorageovertheInternet.1B“DigitalDevices”–computerbasics1.Acomputerisadigitaldevicethatprocessesdataaccordingtoaseriesofstoredinstructionscalledaprogramorsoftware.Computerdataistemporarilystoredinmemory,butisusuallytransferredtostoragewhereitcanbeleftonamorepermanentbasis.Personalcomputersareavailableindesktopandportablemodels.Adigitaldevice,suchasacomputer,iscalleda(n)client,whenitrequestsdatafromaserver.A(n)microcontrollerisaspecial-purposemicroprocessorthatisbuiltintothemachineitcontrols.Acomputeracceptsinput,processesdata,storesdata,andproducesoutput,accordingtoaseriesofinstructions.1C“DigitalDataRepresentation”Datarepresentationreferstotheformatinwhichdataisstored,processed,andtransferred.Digitaldevicesoftenusethebinarynumbersystemtorepresentnumericdata.MostcomputersuseUnicodeorExtendedASCIIcodetorepresentcharacterdata.(Hint:Usetheacronym.)KBistheabbreviationforKilobyte.1D“DigitalProcessing”A(n)compilerconvertsallofthesourcecodeinstructionsintoanewfilecontainingobjectcode.Amicroprocessorishard-wiredtoperformasetofactivitiescalleda(n)instructionset.TheALUinyourcomputer’smicroprocessorholdsdatainregister.Themicroprocessor’scontrolunitcontainsa(n)instructionpointer<指令指針>thatholdstheaddressoftheinstructionbeingexecuted.Thehuman-readableversionofaprogram,createdinahigh-levellanguagebyaprogrammer,iscalledsourcecode.TheALUinyourcomputer’smicroprocessorperformsarithmeticandlogicaloperations.Themicroprocessor’scontrolunitfetcheseachinstruction.1E“PasswordSecurity” Anauthenticationprotocolisanymethodthatconfirmsaperson’sidentityusingsomethingthepersonknows,somethingthepersonpossesses,orsomethingthepersonis.Ona(n)case-sensitiveserver,theuserIDBJPisdifferentfrombjp.A(n)dictionaryattackcanguessyourpasswordifyouareusingcommonpasswordsoreverydaywords.A(n)phishingscamlookslikearequestfromyourbankoranonlinepaymentservice,butisactuallyahackerwhowantsyoutodiscloseyouruserIDandpassword.Chapter2ComputerHardware2A“PersonalComputerBasics”Acomputersystemunithousesthemaincircuitboard,microprocessor,storagedevices,andnetworkcard.DesktopandlaptopcomputerplatformsincludePC,Mac,andLinux.Popularperipheraldevicesincludeprinters,digitalcameras,scanners,joysticks,andspeakers.Todeterminewhethertwocomputersarecompatible,youhavetoconsideriftheyrunthesamesoftwareandusethesameperipheraldevices.Adevicedriverissoftwareusuallyruninthebackgroundwithoutopeningawindowandisdesignedtohelpaperipheraldeviceestablishcommunicationwithacomputer.2B“MicroprocessorsandMemory”ApersonalcomputerwithanIntelCorei7microprocessorislikelytooperateataspeedof3.4GHZ.(Hint:Usetheabbreviation.)A(n)frontsidebusiscircuitrythattransportsdatatoandfromtheprocessor.4004,8088,Athlon,andPentiumarealltypesofmicroprocessor.DDR2,virtual,andvolatilearetermsthatapplytoRAM.(Hint:Usetheacronym.)TheinstructionsforloadingtheoperatingsystemintoRAMwhenacomputerisfirstturnedonarestoredinROM.(Hint:Usetheacronym.)Adualcoreprocessorallowsacomputertoexecutemultipleinstructionsatthesametimetoachieveparallelprocessing.RAMisvolatile,whichmeansthatitcannotholddatawhenthecomputerpowerisoff.AcomputerdoesnotusuallyrunoutofRAMbecauseitcanuseanareaoftheharddiskcalledvirtualmemory.2C“StorageDevices”Accesstimeistypicallyfasterforrandom-accessdevicesthanforsequentialaccessdevices.Amagneticstoragedeviceusesaread-writeheadtomagnetizeparticlesthatrepresentdata.Aharddiskdrivethatisratedataspeedof7200rpm<revolutionsperminute>willgiveyoufasteraccesstoyourdatathanadriveratedat5400.(Hint:Usetheacronym.)CD-Rtechnologyallowsyoutowritedataonadisc,andthenchangethatdata.Trueorfalse?False<可以增加內(nèi)容,但不能更改已經(jīng)加入的內(nèi)容>A(n)SSD<SolidStateDrive>usesthesamestoragetechnologyasaUSBflashdrive,butisnotdesignedtoberemovable.(Hint:Usetheacronym.)Accesstimeistheaveragetimeittakesacomputertolocatedataonastoragemediumandreadit.Adiskdriveisa(n)randomaccessdevice;atapedriveisa(n)sequential<順序的>accessdevice.2D“InputandOutputDevices”O(jiān)netypeofgraphicscircuitry,referredtoasintegratedgraphics<集成顯卡>,isbuiltintoacomputer’ssystemboard.A(n)USBportprovidesoneofthefastest,simplestwaystoconnectperipheraldevices.(Hint:Usetheacronym.)Inthecontextofcomputerdisplaytechnology,responserate<響應(yīng)率>referstothespeedatwhichthescreenimageisrepainted.Thenumberofdotsthatformimagesandtextonamonitororprinterisreferredtoasresolution<分辨率>.VGA,HDMI,andDVIaretypesofexpansionportsthatcanbeusedforconnectingadisplaydevicetoacomputer.Chapter3Software3C“InstallingSoftwareandUpgrades”Mostwebapplicationsrequirenoinstallationandareaccessedthroughabrowser.OnaPC,a(n)setupprogramguidesyouthroughtheinstallationprocess.Portablesoftwarecanbecopiedtoaflashdriveandrunwithoutadditionalinstallation.A(n)servicepackisasetofpatchesthatcorrectproblemsandaddresssecurityvulnerabilities.3D“BuyingSoftware”—SoftwareCopyrightsandLicensesCopyrightlawallowsyoutomakeanextra,orbackup,copyofsoftwareaslongasyoudonotdefeatanycopyprotectionmechanisms.Sharewarethatexpiresafterasetperiodoftimeisoftenfactory-installedonnewcomputers.LibreOffice,Firefox,andLinuxareexamplesofopensourcesoftwarethatcanbelegallymodifiedandredistributed.3E“SecuritySoftware”Acomputerviruscanlurk<潛伏>inacomputerfordaysormonths,quietlyreplicating<復(fù)制>itself.Amass-mailingwormspreadstoothercomputersbysendingitselftoalltheaddressesstoredinthelocale-mailclient.Agroupofzombiecomputerscontrolledbyahackeriscalleda(n)zombie.Avirussignatureisauniquesectionofmaliciouscodethatcanbeidentifiedbyantivirussoftware.Chapter4OperatingSystemandFileManagement4A“OperatingSystemBasics”Anoperatingsystemmanagesacomputer’sresources,suchasRAM,storage,andperipherals<通過應(yīng)用軟件、設(shè)備軟件和硬件>.Mostpersonalcomputeroperatingsystemshavemultitaskingcapabilitiessothattheycansimultaneouslyruntwoormoretasks,jobs,orprograms.Thecorepartofanoperatingsystemiscalleditskernel<常駐內(nèi)存；提供最重要的服務(wù)：內(nèi)存管理、文件夾訪問>.Duringthebootprocess<啟動過程>,aprogram<指BIOS>storedinROMtellstheharddisktoloadtheoperatingsystemIntoRAM.Mostcomputerstodayhavegraphicaluserinterfaces<圖形用戶界面>.Microsoftwindowsfeaturedthefirstgraphicaluserinterface.Trueorfalse?false<不是微軟是詩樂>AnopensourceoperatingsystemcalledLinuxisthefoundationforseveralhandheldoperatingsystems,suchasSymbianandAndroidOS.Thetwomainsoftwarecategoriesareapplicationsoftwareandsystemsoftware.4C“FileSystem”.bmp,docx,exe,and.movareexamplesoffilesextensions.Adiskpartitionisasectionofaharddiskdrivethatistreatedasaseparatestorageunit.4D“FileManagement”Logicalfilestoragemodels,suchasafillingcabinetortreemetaphor,helpyouvisualizetheorganizationofyourcomputerAharddiskstoresdatainconcentriccirclescalledtracks,whicharedividedintowedge-shapedsectors.TheacronymsNTFS,HFS+,andMFTpertainto<從屬于>physicalfilestoragemodels.Chapter5LocalAreaNetworks5A“NetworkBuildingBlocks”Adorm-roomnetworkcoversalimitedareaandisanexampleofalocalareanetwork.Eachconnectionpointonanetworkisreferredtoasanetworknode.Communicationsprotocols,suchasTCP/IP,setstandardsforencodinganddecodingdata,guidingdatatoitsdestination,andmitigatingtheeffectsofnoise.A(n)circuitswitching<電路交換>networkestablishesadedicatedconnectionbetweentwodevices,whereasa(n)packetswitchingnetworkdividesmessagesintosmallparcelsandhandlesthemonafirst-come,first-servedbasis.IPAddresscanbeassignedbyanISPorsystemmanager,orcanbeautomaticallyobtainedfroma(n)DHCP<DynamicHostConfigurationProtocol,動態(tài)主機配置協(xié)議：自動分配動態(tài)地址>server.ToconnecttoaLAN,acomputerrequiresnetworkcircuitry,sometimesreferredtoasanetworkinterfacecard<NIC>.Apeer-to-peernetworkissimplyasmallversionofaclient/servernetwork.Trueorfalse?False<p2p網(wǎng)上各臺計算機有相同的功能，無主從之分，一臺計算機都是既可作為服務(wù)器，設(shè)定共享資源供網(wǎng)絡(luò)中其他計算機所使用，又可以作為工作站，沒有專用的服務(wù)器，也沒有專用的工作站>A(n)dynamicIPaddresscanbeassignedtoanetworkworkstationbyaDHCPserver.5B“WiredandWirelessTechnology”Today’smostpopularwirednetworktechnologyisEthernetandisdefinedbyIEEE802.3standards.Wi-Fiistoday’smostpopularwirelessnetworktechnologyforLAN.Chapter6TheInternet6A“InternetTechnology”TCP/IPistheprimaryprotocolsuiteusedontheInternetisanexampleofanIPv4address,TrueorFalse?TureA(n)domainnameservermaintainsadatabaseofIPaddressesthatcorrespondtoaddressessuchas.MostISPofferasymmetric<非對稱>Internetconnections,meaningthedownstreamspeedisfasterthantheupstreamspeed.TheInternetbackboneisanetworkofhigh-capacitycommunicationslinksthatprovidesthemainroutesfordatatrafficacrosstheInternet.Thetop-leveldomainformostschoolsanduniversitiesisedu.OntheInternet,TCPbreaksamessageintopackets,andIPisresponsibleforaddressingpacketssothattheycanberoutedtotheirdestination.ComputersontheInternetthatactasserversusestaticIPaddresses,whereasmostothercomputersusedynamicIPaddresses.6B“FixedInternetAccess”Dial-upandDSLInternetaccessusethetelephonecablesalreadyinstalledinahomeorbusiness.Trueorfalse?True.ThetworequirementsforcableInternetservicearecircuitryt