《計算機專業(yè)英語》課件第3章

Unit3SoftwareSystemofComputer

教學目標教學內(nèi)容教學目標了解系統(tǒng)軟件的概念以及常見的操作系統(tǒng)了解應用軟件的概念及其特性了解計算機語言的發(fā)展掌握數(shù)據(jù)結構的基本理論掌握關系數(shù)據(jù)庫的相關理論了解多媒體的基本知識了解人工智能的基本理論教學內(nèi)容Text1SystemsoftwareText2ApplicationSoftwareText3ComputerLanguagesText4DataStructuresText5OperatingSystemsText6StructureoftheRelationaldatabaseText7MultimediaText8SoftwareengineeringText9IntroductiontoWindowsText10ArtificialIntelligenceText1SystemsoftwareMainContentsWordsandExpressionsExercisesSoftwareSoftwarereferstocomputerprograms.Programsaretheinstructionsthattellthecomputerhowtoprocessdataintotheformyouwant.Therearetwokindsofsoftware:systemsoftwareandapplicationsoftware.Systemsoftwareisacollectionofprogramsthatenablesapplicationsoftwaretorunonacomputersystem'shardwaredevices,itisbackgroundsoftwareandincludesprogramsthathelpthecomputermanageitsowninternalresources.Applicationsoftwareisaspecializedprogramsthatenablestheusertoaccomplishspecifictasks.SystemsoftwareSystemsoftwareconsistsoffourkindsofprograms:bootstraploader,diagnosticroutines,basicinput-outputsystem,andoperatingsystem.Amongthesefourparts,theoperatingsystemiswemostconcernedwith,whichhelpsmanagecomputerresources.Mostimportantoperatingsystemsare:Windows,WindowsNT,OS/2,Macintosh,andUnix.Windows

Windowsgetsitsnamebecauseofitsabilitytorunmultipleapplicationsatthesametime,eachinitsownwindow.Windowsoffersgraphicaluserinterface(GUI),presentstheuserwithgraphicimagesofcomputerfunctionsanddata.Itprovidesastandardmechanismforcopyingormovinginformationfromoneprogramtoanother.Thismechanism,calledtheclipboard,meansthatinformationcreatedinonecontextisinstantlyreusableinanother,youdon'tneedtoreenterinformationorworkwithclumsydata-transferutilities.WindowsalsohasDDE(dynamicdataexchange)andOLE(objectlinkingandembedding)functions.InDDEtwoormoreapplicationscanbelinked.Thisway,datacreatedinoneapplicationisautomaticallyenteredintotheothers.OLE,likeDDE,linksdatabetweenapplications.Additionally,OLEallowstheapplicationreceivingthedatatodirectlyaccesstheapplicationthatcreatedthedata.

WindowsNTWindowsNTisanoperatingsystemdesignedtorunonawiderangeofpowerfulcomputersandmicrocomputers.Itisaverysophisticatedandpowerfuloperationsystem.DevelopedbyMicrosoft,WindowsNTisnotconsideredareplacementforWindows.Rather,itisanadvancedalternativedesignedforverypowerfulmicrocomputersandnetworks.WindowsNThastwomajoradvantageswhencomparetoWindows:MultiprocessingItissimilartomultitaskingexceptthattheapplicationsarerunindependentlyatthesametime.Forinstance,youcouldbeprintingawordprocessingdocumentandusingadatabasemanagementprogramatthesametime.Withmultitasking,thespeedatwhichthedocumentisprintedisaffectedbythedemandsofthedatabasemanagementprogram.Withmultiprocessing,thedemandsofthedatabasemanagementprogramdonotaffecttheprintingofthedocument.NetworkingInmanybusinessenvironments,workersoftenusecomputertocommunicatewithoneanotherandtosharesoftwareusinganetwork.Thisismadepossibleandcontrolledbyspecialsystemsoftware.WindowsNThasnetworkcapabilitiesandsecuritychecksbuiltintotheoperatingsystem.Thismakesnetworkinstallationanduserelativelyeasy.OS/2OS/2wasdevelopedjointlybyIBMandMicrosoftCorporation.OS/2hasmanysimilaritieswithWindowsNT.Itisdesignedforverypowerfulmicrocomputersandhasseveraladvancedfeatures.SomeofitsadvantagesoverWindowsNTinclude:MinimumsystemconfigurationLikeWindowsNT,OS/2requiressignificantmemoryandharddiskspace.However,OS/2requiresslightlyless.WindowsapplicationLikeWindowsNT,OS/2doesnothavealargenumberofapplicationprogramswrittenespeciallyforit.OS/2canalsorunWindowsprograms,butitrunstheseprogramsslightlyfasterthanWindowsNT.CommonuserinterfaceMicrocomputerapplicationprogramswrittenspecificallyforWindowsNT,aswellasforOS/2,haveconsistentgraphicsinterfaces.Acrossapplications,theuserisprovidedwithsimilarscreendisplays,menus,andoperations.Additionally,OS/2offersaconsistentinterfacewithmainframes,minicomputers,andmicrocomputers.MacintoshOperationSystemTheMacintoshSoftware,whichrunsonlyonMacintoshcomputers,offersahigh-qualitygraphicaluserinterfaceandisveryeasytouse.AppleMacintoshSystem7.5designedforApplecomputersusingMotorola'sPowerPCmicroprocessor,isasignificantmilestoneforApple.ItisaverypowerfuloperatingsystemlikeWindowsNTandOS/2.System7.5hasnetworkcapabilitiesandcanreadWindowsandOS/2files.Ithasseveraladvantages:EaseofuseThegraphicaluserinterfacehasmadetheMacintoshpopularwithmanynewcomerstocomputing.Thisbecauseitiseasytolearn.QualitygraphicsMacintoshOperationSystemMacintoshhasestablishedahighstandardforgraphicsprocessing.ThisisaprincipalreasonwhytheMacintoshispopularfordesktoppublishing.Usersareeasilyabletomergepictorialandtextmaterialstoproducenearlyprofessional-lookingnewsletters,advertisements,andthelike.ConsistentinterfacesMacintoshapplicationshaveaconsistentgraphicsinterface.Acrossallapplications,theuserisprovidedwithsimilarscreendisplays,menus,andoperations.MultitaskingLikeWindows,WindowsNT,andOS//2,theMacintoshSystemenablesyoutodomultitasking.Thatis,severalprogramscanrunatthesametime.CommunicationsbetweenprogramsTheMacintoshsystemallowsapplicationsprogramstosharedataandcommandswithotherapplicationsprograms.UnixUnixwasoriginallydevelopedbyAT&Tforminicomputersandisverygoodformultitasking.Itisalsogoodfornetworkingbetweencomputers.UnixinitiallybecamepopularinindustrybecauseformanyyearsAT&Tlicensedthesystemtouniversitiesforanominalfee.Itispopularamongengineersandtechnicalpeople,withthearrivalofverypowerfulmicrocomputers,Unixisbecomingalargerplayerinthemicrocomputerworld.Unixcanbeusedwithdifferenttypesofcomputersystems,thatis,itisaportableoperatingsystem.Itisusedwithmicrocomputers,minicomputers,mainframes,andsupercomputers.Theotheroperatingsystemsaredesignedformicrocomputersandarenotnearlyasportable.Italsohastheadvantagesofmultitasking,multiprocessing,multiuser,andnetworking.WordsandExpressionssystemsoftware系統(tǒng)軟件applicationsoftware應用軟件accomplish[?'k?mpli?;?'k?m-]vt.達到(目的)；完成(任務、使命、計劃、事業(yè)等)；實現(xiàn)(諾言、計劃等)：diagnosticroutines【計算機】診斷(例行)程序[亦作diagnosticsubroutine,diagnostictest]basicinput-outputsystem基本輸入輸出系統(tǒng)operatingsystem操作系統(tǒng)graphicaluserinterface(GUI)圖形用戶界面mechanism['mek?niz?m]n.機械,機構,結構機制，原理reenter[,ri:'ent?]vt.再進入；重返OLE(objectlinkingandembedding)functions對象連接與嵌入功能DDE(dynamicdataexchange)動態(tài)數(shù)據(jù)交換clipboard[‘klipb?:d]n.剪貼板WordsandExpressionssophisticated[s?'fistikeitid]adj.（系統(tǒng)、流程、技術等)極其復雜的，精密的，尖端的，發(fā)達的replacement[ri'pleism?nt]n.交換,更換,代替者21世紀大英漢詞典》

alternative[?:l't?:n?tiv]adj.1.兩者(或兩者以上)擇一的，二擇其一的，可從數(shù)個中任擇其一的；(兩種選擇中)非此即彼的2.供替代的；供選擇的3.(兩者)互斥的independently[indi'pend?ntli]adv.獨立地,自立地milestone['mailst?un]n.里程碑merge[m?:d?]vt.【計算機】合并pictorial[pik't?:ri?l]adj.1.圖片的；用圖片表示的；由圖片組成的；2.形象化的；生動的newsletters['nju:z,let?(r)]n.時事通訊,時事分析,時事傳報21世紀大英漢詞典》

AT&T美國電話電報公司(財富500強公司之一，總部所在地美國,主要經(jīng)營電訊)portable['p?:t?bl]adj.【計算機】可移植的，不經(jīng)修改便可在任何計算機上使用的multiprocessing[,m?lti'pr?usesi?;-'pr?-]n.【計算機】多重處理(使用兩個以上通往同一記憶系統(tǒng)的電腦處理機，能同時處理多項程序)，多道處理ExercisesI.Trueorfalse?Ifcorrect,writeTinparentheses;Otherwise,writeF.（）1.Systemsoftwareisaspecializedprogramsthatenablestheusertoaccomplishspecifictasks.（）2.Theoperatingsystemhelpsmanagecomputerresources.（）3.Windowsgetsitsnamebecauseofitsabilitytorunmultipleapplicationsatthesametime,eachinitsownwindow.（）4.WindowsalsohasDDE(dynamicdataexchange)andOLE(objectlinkingandembedding)functions.（）5.OLEdon’tallowtheapplicationreceivingthedatatodirectlyaccesstheapplicationthatcreatedthedata.（）6.Withmultiprocessing,thedemandsofthedatabasemanagementprogramdoaffecttheprintingofthedocument.（）7.WindowsNThasnetworkcapabilitiesandsecuritychecksbuiltintotheoperatingsystem.Thismakesnetworkinstallationanduserelativelyeasy.（）8.OS/2wasdevelopedonlybyMicrosoftCorporation.（）9.TheMacintoshSoftware,whichrunsonlyonMacintoshcomputers,offersahigh-qualitygraphicaluserinterfaceandisveryhardtouse.（）10.UnixwasoriginallydevelopedbyAT&Tforminicomputersandisverygoodformultitasking.ExercisesII.Fillintheblankswithproperwords.1.Softwarereferstocomputerprograms.__________aretheinstructionsthattellthecomputerhowtoprocessdataintotheformyouwant.2.Therearetwokindsofsoftware:systemsoftwareand__________software.3.__________softwareisacollectionofprogramsthatenablesapplicationsoftwaretorunonacomputersystem'shardwaredevices,itisbackgroundsoftwareandincludesprogramsthathelpthecomputermanageitsowninternalresources.4.__________softwareconsistsoffourkindsofprograms:bootstraploader,diagnosticroutines,basicinput-outputsystem,andoperatingsystem.5.Windowsoffers__________,presentstheuserwithgraphicimagesofcomputerfunctionsanddata.6.LikeWindows,WindowsNT,andOS//2,theMacintoshSystemenablesyoutodo__________Thatis,severalprogramscanrunatthesametime.7.Unixisbecomingalargerplayerinthemicrocomputerworld.Unixcanbeusedwithdifferenttypesofcomputersystems,thatis,itisaportableoperatingsystem.Itisusedwithmicrocomputers,minicomputers,__________,andsupercomputers.Text2ApplicationSoftwareMainContentsWordsandExpressionsExercisesApplicationsoftwareApplicationsoftwaremightbedescribedasend-usersoftware.Applicationsoftwareperformsusefulworkongeneral-purposetaskssuchaswordprocessingandcostestimating.Therearecertaingeneral-purposeprogramsthatarewidelyusedinnearlyallcareerareas.Theyarewordprocessing,electronicspreadsheets,graphicprogramsandsoon.Theyarealsocalledbasictoolsandhavesomecommonfeatures.InsertPointMenusHelpButtonBarsDialogBoxScrollBarsWYSIWYGFunctionKeysWordprocessingsoftware

Wordprocessingsoftwareisusedtocreate,edit,save,andprintdocuments.Documentscanbeanykindoftextmaterial.Withwordprocessing,youviewthewordsyoutypeonamonitorinsteadofonapieceofpaper.Afteryoufinishyourtyping,saveyourwordsondiskettesorharddisk,andprinttheresultsonpaper.Thebeautyofthismethodisthatyoucanmakechangesorcorrectionsbeforeprintingoutthedocument.Evenafteryourdocumentisprintedout,youcaneasilygobackandmakechanges.Youcanthenprintitoutagain.Wanttochangeareportfromdoublespacedtosinglespaced?Alterthewidthofthemarginsontheleftandright?Deletesomeparagraphsandaddsomeothersfromyetanotherdocument?Awordprocessorallowsyoutodoallthesewithease.Indeed,deleting,inserting,andreplacing—theprincipalcorrectingactivities—canbedonejustbypressingkeysonthekeyboard.PopularwordprocessingsoftwareareWord,WPSandsoon.Theyhavesomecommonfeatures.WordWrapandtheEnterKeyOnebasicwordprocessingfeatureiswordwrap.Whenyoufinishaline,awordprocessordecidesforyouandautomaticallymovestheinsertionpointtothenextlines.Tobeginanewparagraphorleaveablankline,youpresstheEnterkey.SearchandReplaceAsearchorfindcommandallowsyoutolocateanycharacter,word,orphraseinyourdocument.Whenyousearch,theinsertionpointmovestothefirstplacetheitemappears.Ifyouwant,theprogramwillcontinuetosearchforallotherlocationswheretheitemappears.Thereplacecommandautomaticallyreplacesthewordyousearchforwithanotherword.Thesearchandreplacecommandsareusefulforfindingandfixingerrors.Cut,Copy,andPasteWithawordprocessor,youselecttheportionoftexttobemovedbyhighlightingit.Usingeitherthemenuorbuttonbar,choosethecommandtocuttheselectedtext.Theselectedtextdisappearsfromyourscreen.Thenmovetheinsertionpointtothenewlocationandchoosethepastecommandtoreinsertthetextintothedocument.Inasimilarmanner,youcancopyselectedportionsoftextfromonelocationtoanother.SpreadsheetAspreadsheetisanelectronicworksheetusedtoorganizeandmanipulatenumbersanddisplayoptionsforanalysis.Spreadsheetsareusedbyfinancialanalysts,accountants,contractors,andothersconcernedwithmanipulatingnumericdata.Spreadsheetsallowyoutotryoutvarious"what-if"kindsofpossibilities.Thatisapowerfulfeature.Youcanmanipulatenumbersbyusingstoredformulasandcalculatedifferentoutcomes.

Aspreadsheethasseveralparts.Theworksheetareaofthespreadsheethaslettersforcolumnheadingsacrossthetop.Italsohasnumbersforrowheadingsdowntheleftside.Theintersectionofacolumnandrowiscalledacell.Thecellholdsasingleunitofinformation.Thepositionofacelliscalledthecelladdress.Forexample,"A1"isthecelladdressofthefirstpositiononaspreadsheet,thetopmostandleftmostposition.Acellpointer—alsoknownasthecellselector—indicateswheredataistobeenteredorchangedinthespreadsheet.Thecellpointercanbemovedaroundinmuchthesamewaythatyoumovetheinsertionpointerinawordprocessingprogram.Excelisthemostcommonspreadsheetsoftware.Ithassomecommonfeaturesofspreadsheetprograms.FormatLabelisoftenusedtoidentifyinformationinaworksheet,itisusuallyawordorsymbol.Anumberincelliscalledavalue.Labelsandvaluescanbedisplayedorformattedindifferentways.Alabelcanbecenteredinthecellorpositionedtotheleftorright.Avaluecanbedisplayedtoshowdecimalplaces,dollars,orpercent.Thenumberofdecimalpositionscanbealtered,andthewidthofcolumnscanbechanged.FormulasOneofthebenefitsofspreadsheetsisthatyoucanmanipulatedatathroughtheuseofformulas.Formulasareinstructionsforcalculations.Theymakeconnectionsbetweennumbersinparticularcells.FunctionsFunctionsarebuilt-informulasthatperformcalculationsautomatically.RecalculationRecalculationorwhat-ifanalysisisoneofthemostimportantfeaturesofspreadsheets.Ifyouchangeoneormorenumbersinyourspreadsheet,allrelatedformulaswillrecalculateautomatically.Thusyoucansubstituteonevalueforanotherinthecellsaffectedbyyourformulaandrecalculatetheresults.Formorecomplexproblems,recalculationenablesyoutostorelong,complicatedformulasandmanychangingvaluesandquicklyproducealternatives.WordsandExpressionsgeneral-purposetasks通用任務wordprocessingn.【計算機】字處理costestimating成本計算electronicspreadsheets電子表單graphicprograms圖形程序cursor['k?:s?]n.【計算機】1.(顯示器的)光標2.光標移動器，鼠標ablinkingverticalbar閃爍的豎線光標thedirectionalarrowkeys方向鍵pull-downmenu下拉菜單representation[,reprizen'tei??n]n.表示法,表現(xiàn),陳述，答辯Dialogboxes對話欄WordsandExpressionsScrollbars滾動條preview['pri:'vju:]n.事先查看,查閱v.事先查看,查閱diskette['disket]n.【計算機】軟(磁)盤，塑料磁盤(=floppydisk)margin['mɑ:d?in]n.(時間,金錢)富余,利潤,頁邊空白,邊緣cut[k?t]n.【計算機】剪切copy['k?pi]n.【計算機】復制paste[peist]n.【計算機】粘貼highlighting['hai,laiti?]n.加亮formulas['f?:mjul?]n.公式,配方,規(guī)則；嬰兒食品calculations[,k?lkju'lei??n]n.計算recalculate[ri'k?lkjuleit]vt.再計算(再核算,再估計,換算)substitute['s?bstitju:t]n.代替者,代用品v.代替vi.(for)代替vt.用...代替,代以ExercisesI.Trueorfalse?Ifcorrect,writeTinparentheses;Otherwise,writeF.（）1.Youcannotmovetheinsertpointaroundusingamouseorthedirectionalarrowkeysonmanykeyboards.（）2.Scrollbarsenableyoutodisplayadditionalinformationnotcurrentlyvisibleonthescreen.（）3.ApplicationprogramswithoutWYSIWYGcanalwaysdisplayanexactrepresentationofthefinalprinteddocument.（）4.Functionkeysdoidenticalthingsindifferentsoftwarepackages.（）5.Whenyousearch,theinsertionpointmovestothefirstplacetheitemappears.Ifyouwant,theprogramwillcontinuetosearchforallotherlocationswheretheitemappears.（）6.Aspreadsheetisanelectronicworksheetusedtoorganizeandmanipulatenumbersanddisplayoptionsforanalysis.（）7.Oneofthebenefitsofspreadsheetsisthatyoucanmanipulatedatathroughtheuseofformulas.Formulasareinstructionsforcalculations.Theymakeconnectionsbetweennumbersinparticularcells.ExercisesII.Fillintheblankswithproperwords.1.Theinsertpointor__________showsyouwhereyoucanenterdatanext.2.Typically,themenusaredisplayedinamenu__________atthetopofthescreen.3.__________standsfor“WhatYouSeeIsWhatYouGet.”4.TheWYSIWYGfeatureallowstheusertopreviewthedocument'sappearance__________itisprintedout.5.With__________processing,youviewthewordsyoutypeonamonitorinsteadofonapieceofpaper.6.A__________orfindcommandallowsyoutolocateanycharacter,word,orphraseinyourdocument.7.The__________commandautomaticallyreplacesthewordyousearchforwithanotherword.Thesearchandreplacecommandsareusefulforfindingandfixingerrors.8.Usingeitherthemenuorbuttonbar,choosethecommandtocuttheselectedtext.Theselectedtextdisappearsfromyourscreen.Thenmovetheinsertionpointtothenewlocationandchoosethe__________commandtoreinsertthetextintothedocument.9.__________orwhat-ifanalysisisoneofthemostimportantfeaturesofspreadsheets.Ifyouchangeoneormorenumbersinyourspreadsheet,allrelatedformulaswillrecalculateautomatically.Text3ComputerLanguagesMainContentsWordsandExpressionsExercisesProgramminglanguagesProgramminglanguagesdatebackalmosttotheinventionofthedigitalcomputerinthe1940s.Computerlanguageshaveundergonedramaticevolutionsincethefirstelectroniccomputerswerebuilt.Earlyon,programmersworkedwiththemostprimitivecomputerinstructions—machinelanguage.Theseinstructionswererepresentedbylongstringsofonesandzeroes.Thefirstassemblylanguagesemergedinthelate1950swiththeintroductionofcommercialcomputers.Itmapsmachineinstructionstohuman-readablemnemonics,suchasADDandMOV.Computerprogrammersuseassemblylanguagestomakemachine-languageprogramseasiertowrite.Thefirstprocedurallanguagesweredevelopedinthelate1950stoearly1960s:FORTRAN,createdbyJohnBackus1,andthenCOBOL,createdbyGraceHopper.ThefirstfunctionallanguagewasLISP,writtenbyJohnMcCarthyinthelate1950s.Althoughheavilyupdated,allthreelanguagesarestillwidelyusedtoday.Inthelate1960s,thefirstobject-orientedlanguages,suchasSIMULA,emerged.Logiclanguagesbecamewellknowninthemid1970swiththeintroductionofPROLOG3,alanguageusedtoprogramartificialintelligencesoftware.Duringthe1970s,procedurallanguagescontinuedtodevelopwithALGOL,BASIC,PASCAL,C,andAda.SMALLTALK6wasahighlyinfluentialobject-orientedlanguagethatledtothemergingofobject-orientedandprocedurallanguagesinC++andmorerecentlyinJAVA.Althoughpurelogiclanguageshavedeclinedinpopularity,variationshavebecomevitallyimportantintheformofrelationallanguagesformoderndatabases,suchasSQL.Intime,higher-levellanguagesevolved,suchasPASCAL,BASIC,COBOL,C,C++,andJAVA.High-levellanguagesarerelativelysophisticatedsetsofstatementsutilizingwordsandsyntaxfromhumanlanguage.Theyaremoresimilartonormalhumanlanguagesthanassemblyormachinelanguagesandarethereforeeasiertouseforwritingcomplicatedprograms.Theproblemsprogrammersareaskedtosolvehavebeenchanging.Today'sprogramsusesophisticated"user-friendlyinterfaces,"involvingmultiplewindows,menus,anddialogboxes.Theprogramswrittentosupportthisnewapproacharefarmorecomplexthanthosewrittenjusttenyearsago.Generally,asprogrammingrequirementshavechanged,bothlanguagesandthetechniquesusedforwritingprogramshaveevolved.WordsandExpressionsundergo[,?nd?'g?u]v.遭受,經(jīng)歷,忍受evolution[,i:v?'lu:??n,,ev?-]n.進化,發(fā)展,進展primitive['primitiv]adj.原始的n.原始人human-readableadj.人可讀的mnemonics[ni:'m?niks]n.記憶術，記憶法assemblylanguage匯編語言correspond[k?ris'p?nd]v.符合,通信,相當roughly['r?fli]adv.概略地,粗糙地aid[eid]n.幫助,有幫助的事物v.援助,幫助manipulate[m?'nipjuleit]v.操縱,利用,假造[計算機]操作dot[d?t]n.點,圓點,小孩子,小東西v.作小點記號,加小點于,點綴[計算機]點procedurallanguage過程語言WordsandExpressionspopularity[,p?pju'l?riti]n.普及,流行variation[,v??ri'ei??n]n.變化,變動,變種,變異vitally['vait?li]adv.與生命有關地,致命地,緊要地syntax['sint?ks]n.句法complicated['k?mplikeitid]adj.復雜的,難懂的approximating[?'pr?ksimit]adj.大約的,近似的v.接近,約等于interpreter[in't?:prit?]n.譯員,口譯者compiler[k?m'pail?]編譯器,編譯程序intermediary[,int?'mi:di?ri]n.仲裁者,調(diào)解者,媒介物adj.中間的,媒介的[計算機]媒介invoke[in'v?uk]v.[計算機]調(diào)用linker['li?k?]n.[計算機]鏈接器executable['eksikju:t?bl]adj.可執(zhí)行的spot[sp?t]n.污點,地點,斑點adj.當場的,現(xiàn)實買賣的v.污點,認出,用燈光照射ExercisesI.Trueorfalse?Ifcorrect,writeTinparentheses;Otherwise,writeF.（）1.Earlyon,programmersworkedwiththemostprimitivecomputerinstructions—machinelanguage.Theseinstructionswererepresentedbylongstringsofzeroesandtwos.（）2.Anassemblylanguagestatementiscomposedwiththeaidofeasytoremembercommands.（）3.ThecommandtoaddthecontentsofthestorageregisterAtothecontentsofstorageregisterBmightbewrittenADDA,Binatypicalassemblylanguagestatement.（）4.Assemblylanguagessharecertainfeatureswithmachinelanguages.（）5.Programmersusemachinelanguageswhenitisimportanttominimizethetimeittakestorunaprogram,becausethetranslationfromassemblylanguagetomachinelanguageisrelativelysimple.（）6.Inthelate1960s,thefirstobject-orientedlanguages,suchasFORTRAN,emerged.（）7.High-levellanguagesarelesssimilartonormalhumanlanguagesthanassemblyormachinelanguagesandarethereforeeasiertouseforwritingcomplicatedprograms.（）8.Programswritteninahigh-levellanguagemaytakelongertoexecuteanduseupmorememorythanprogramswritteninanassemblylanguage.（）9.Becausethetime-consumingtaskoftranslatingthesourcecodeintomachinelanguagehasalreadybeenaccomplished,compilersproduceaprogramthatisveryfasteachtimeitisrun.ExercisesII.Fillintheblankswithproperwords.1.Computerprogrammersuseassemblylanguagestomake__________programseasiertowrite.2.__________languagesarealsousedwhensomepartofthecomputerhastobecontrolleddirectly,suchasindividualdotsonamonitorortheflowofindividualcharacterstoaprinter.3.__________languagesarerelativelysophisticatedsetsofstatementsutilizingwordsandsyntaxfromhumanlanguage.4.A__________translatesthecodeintoanintermediaryform.Thisstepiscalledcompiling,andproducesanobjectfile.5.Thecompilertheninvokesa__________,whichturnstheobjectfileintoanexecutableprogram.Text4DataStructuresMainContentsWordsandExpressionsExercisesDataStructuresAsingleintegercanbeveryusefulifweneedacounter,asum,oranindexinaprogram,butgenerallywemustalsodealwithdatathathavelotsofparts,suchasalist.Wedescribethelogicalpropertiesofsuchacollectionofdataasanabstractdatatype;wecalltheconcreteimplementationofthedataadatastructure.Whenaprogram’sinformationismadeupofcomponentparts,wemustconsideranappropriatedatastructure.Datastructureshaveafewfeaturesworthnoting.First,theycanbe“decomposed”intotheircomponentelements.Second,thearrangementoftheelementsisafeatureofthestructurethataffectshoweachelementisaccessed.Third,boththearrangementoftheelementsandthewaytheyareaccessedcanbeencapsulated.Weusethesameapproachtodatastructuresinourprograms.Adatastructureisdefinedby(1)thelogicalarrangementofdataelements,combinedwith(2)thesetofoperationsweneedtoaccesstheelements.Inmodelingdatainaprogram,wewearmanyhats.Thatis,wemustdeterminethelogicalpictureofthedata,choosetherepresentationofthedata,anddeveloptheoperationsthatencapsulatethisarrangement.Duringthisprocess,weconsiderdatafromthreedifferentperspectives,orlevels:1.Application(oruser)level:Awayofmodelingreal-lifedatainaspecificcontext;alsocalledtheproblemdomain.2.Logical(orabstract)level:Anabstractviewofthedatavalues(thedomain)andthesetofoperationstomanipulatethem.3.Implementationlevel:Aspecificrepresentationofthestructuretoholdthedataitems,andthecodingoftheoperationsinaprogramminglanguage(iftheoperationsarenotalreadyprovidedbythelanguage).Withouttellinghowtheoperationswork.Ittellswhatbutnothow.Forinstance,theabstractviewofcheckinginabookcanbesummarizedinthefollowingspecification:Theonlycommunicationfromtheuserintotheimplementationleveloccursintermsofinputspecificationsandallowableassumptions—thepreconditionsoftheaccessingroutines.Theonlyoutputfromtheimplementationlevelbacktotheuseristhetransformeddatastructuredescribedbytheoutputspecifications,orpostconditions,oftheroutines.Theabstractviewhidesthedatastructure,butprovideswindowsintoitthroughthespecifiedaccessingoperations.WordsandExpressionsconsiderablyadv.相當?shù)兀环浅５豷ubsume[s?b'sju:m]vt.把……歸入；把……包括在內(nèi)abstractdatatype[計]抽象數(shù)據(jù)類型comprehensive[,k?mpri'hensiv]adj.廣泛的；綜合的representative[,repri'zent?tiv]a.代表性的succinctlyadv.簡潔地；簡便地propertiesn.性能；道具，內(nèi)容（property的復數(shù)