[]
one国开-假定一个笛卡儿积中有m个元组，在由它所产生的任何一个关系中，其元组数必然小于等于m。（）
内容版权声明：除非注明，否则皆为本站原创文章。
转载注明出处：
相关推荐
- 日期：2026-06-100one国开-关系数据模型是以二维表为基础的。（）
- 日期：2026-06-101one国开-—Mike,howwouldyouliketogotoFrankfurt?—
- 日期：2026-06-102one国开-–Thougheveryoneplayedwell,welostthegame.–__________________.
- 日期：2026-06-103one国开-—IwonderifIcoulduseyourcomputertonight?—________________________
- 日期：2026-06-104one国开-—Sorry,Imadeamistakeagain.—_______________Practisemore,andyou’llsucceed.
- 日期：2026-06-105one国开---Areyoureadytobuyacar,Sir?--__________________
- 日期：2026-06-106one国开-WorkingforGoogleisadreamofmany,notjustbecauseofwhatthiscompanyhasachievedinthelast15years,butbecauseofitsenviableworkculture.Withabout37,000employeesin40countries,youmightwonderhowGooglemaintainsamotivatingworkexperiencethroughoutitsentirecompany.WorkingforGooglecomeswithperksthatmostotherorganizationscan’tprovide–bowlingalleys,freehaircuts,gymmemberships,andshuttlestoandfromwork.Thecompany’ssecrettosuccessisputtingthesameamountoftimeandeffortintokeepingemployeeshappyasitdoesintoinnovatingproducts.Backwhenthecompanywasjustastart-up,co-foundersLarryPageandSergeyBrinhadthegoalofmakingGoogleaplacethemosttalentedpeoplewantedtoworkat.Theirideawassimple:creatingaworkculturethatkeepsemployeeshappywillmotivatethemtodotheirbestandwillkeepthemloyaltothecompany.“It’slessabouttheaspirationtobeNo.1intheworld,andmorethatwewantouremployeesandfutureonestoloveithere,becausethat’swhat’sgoingtomakeussuccessful,”saidKarenMay,theVicePresidentofpeopledevelopmentatGoogle.Googlealsomakesitsemployeeswanttoworkbecausemanagersprovidetasksthatareinspiringandchallenging.EveryemployeeatGooglehastheopportunitytospend20%ofhisorherworkingtimeonaprojecttheychoose.Thisfreedomtakesemployeesoutoftheirroutineandawayfromthemundanetasksthatoftenmakeworkersfeeluninspiredabouttheirjobs.Lastly,Googleshowseachemployeejusthowimportantheorsheistothecompany.Eachemployee,regardlessofherspotonthetotempole,hasaninfluenceonhowGoogleperforms.“Ifyouvaluepeople,andcareaboutthemaswholepeople,onethingyoudoisgivingthemavoice,andyoureallylisten,”Maysaid.GoogledoesjustthatbyhostingemployeeforumseveryFriday,wheretheydiscussthe20most-askedquestions.Employeeshaveaccesstoallcompanyinformation,addingasenseoftrust,andemployeesandleadersworktogethertosolveproblems.1.WhydomanypeoplewanttoworkforGoogle?(1)A.Becausetheycanmakemuchmoney.B.Becausetheycanenjoytheworkingatmosphere.C.Becausetheycangetthechancetoworkabroad.D.Becausetheycanaccesstoallcompanyinformation.2.WorkingforGooglecangettheextrabenefitsexcept(2).A.mealsforfreeB.freetransportationC.freeentertainingD.haircutsforfree3.WhofoundedGoogle?(3)A.LarryPageandSergeyBrin.B.KarenMay.C.SergeyBrin.D.BillGates.4.IfyouareanormalemployeeofGoogle,youcouldnot(4).A.discussquestionswithyourleadersB.onlyworkfortheprojectyouchooseC.playbowlingwithyourcolleaguesandgetawayfrommundaneerrandsD.createaworkculture5.WhatisGoogle’ssecrettosuccess?(5)A.Innovatinghi-techproducts.B.Payinghighsalarytotheemployeesandpracticingstrictmanagement.C.Valuingthehappinessofitsemployeesasmuchasinnovatinggoodproducts.D.Providingmoretrainingtotheemployees.
- 日期：2026-06-107one国开-Whencomputerserversoperateacomplexprogram,theycangetveryhot.Coolingtheserverscanbecostly.Soresearchersaskedwhatwouldhappeniftheheatcreatedbytheserverscouldbecapturedandused?DatacentersoflargeInternetcompaniessuchasGoogleandMicrosofthavethousandsofcomputerservers.Astheseserversprocessinformation,theycreatelargeamountsofheat,sotheyneedhugecoolingsystems.Thesesystemssendtheheatintotheair.TheDutchcompanyNerdalizethinkspayingforelectricitytooperatetheserversandthenpayingagaintocoolthemisawasteofenergy.Soitdevelopedadevicecalledthee-Radiator.Itisacomputerserverthatalsoworksasaheatingsource.BoazLeupeisthechiefexecutiveofficerofNerdalize.Hesaysthee-Radiatorsavesmoneybecausecompaniesdon’thavetopaytocooltheirservers.“Thekilowatt（千瓦）houryouareusingisusedtwice—oncetoheatthehomeandoncetocomputetheclient’staskwithoutthecoolingoverhead.”HesaysfivehomeownersintheNetherlandsaretestingtheheatingdeviceintheirhomes.“Wereimbursetheelectricitytheserveruses,andthatwecandobecauseofthecomputerclientsontheotherside,and,inthatway,homeownersactuallygetheatingforfree,andcomputerusersdon’thavetopayfortheoverheadofthedatacenter.”JanVisserisoneoftheparticipantsintheyear-longexperiment.Hesaystheamountofheatproducedbythee-Radiatordependsontheworkbeingdonebythecomputerserver.Hesaysitcannotbeusedastheprimarysourceofheat.Butheisreadytotryit.Hesaysifitprovidesenoughwarmth,hewillbeabletousehishome’sheatingsystemless,whichwillsavehimmoney.Nerdalizesayse-Radiatorscreateheattemperaturesofupto55℃.Itsaysthedevicescouldsaveusersupto$440inheatingcostsayear.1.Whatwouldhappenifcoolingcomputerservers?(1)A.Computerscangetveryhot.B.Computerserverscancatchfireeasily.C.Companieswillpaymoreexpense.D.Companieswillpaylessexpense.2.ThecomputerserversinlargeInternetcompaniescan.(2)A.createlargeamountsofinformationB.createalargequantityofheatC.managethehugecoolingsystemsD.managethehugeheatingsystems3.WhatistheviewpointofDutchcompanyNerdalizeonthecurrentsystems？(3)A.ItthinksthatthelargeInternetcompaniesneedcooling.B.Itthinksthatthecurrentsystemsarewastesofenergy.C.ItthinksthatthelargeInternetcompaniesneedpayingforelectricity.D.Itthinksthatthecurrentsystemsaresavingtheenergy.4.AccordingtoJanVisser,theamountofheatproducedbythee-Radiator.(4)A.dependsontheworkbeingprocessedbyPCB.cannotbeusedasthehome’sheatingsystemC.cannotbeusedasthemainsourceofheatD.dependsontheinformationprocessedbyserver5.Thebesttitleforthispassageis.(5)A.ANewWaytoHeatHomesB.ANewWaytoCoolHomesC.HotComputersCouldBeUsedforFreeD.E-Radiator,theprimarysourceofheat
- 日期：2026-06-108one国开-从教学库的选课表中查询出每个课程号所对应的课程被选修的学生人数。
- 日期：2026-06-109one国开-从教学库的选课表中查询出成绩大于等于90的所有记录。
- 日期：2026-06-1010one国开-select专业,count(*)as人数from学生groupby专业orderby专业
- 日期：2026-06-1011one国开-selectdistinct姓名,专业from学生,选课where学生.学生号=选课.学生号
- 日期：2026-06-1012one国开-select*from选课where学生号='0303001'
- 日期：2026-06-1013one国开-在Access的窗体中，可以输入、编辑和显示来自数据表的数据
- 日期：2026-06-1014one国开-从教学库的选课表中查询出每个学生被选修的课程门数。
- 日期：2026-06-1015one国开-从教学库的选课表中查询出成绩大于等于70，同时小于等于90的所有记录。
- 日期：2026-06-1016one国开-select课程学分from课程where课程名='操作系统'
- 日期：2026-06-1017one国开-在Access中，对窗体和报表进行复制和导出等操作时，其相关的事件过程将不会跟着被复制和导出。（）
- 日期：2026-06-1018one国开-利用宏操作不能够打开或关闭表、查询、窗体等对象。（）
- 日期：2026-06-1019one国开-可以利用“空报表”和“报表设计”命令，向报表中添加相关的控件。（）