计算分析浓度为0.10mol∙L-1的Na2HPO4水溶液的pH值()。(已知H3PO4的pKa1～pKa3分别是2.12、7.20、12.36.)

已知某投资项目的原始投资额为100万元，投资期为2年，投产后第1～3年每年现金净流量为25万元，第4～10年每年现金净流量为20万元。则该项目包括投资期的静态回收期为（　　）。

生产工人小李的月标准工资2000元，12月份出勤20天，病假2天，事假1天，缺勤期间无法定节假日，本月共8个休息日，其病假工资按80%计发，则月薪制下，每月按30天计算，小李本月应得工资额为（）元。

表达“从一个关系的所有行中提取出满足某些条件的行”，“从一个关系的所有列中提取出某些列”“提取出属于一个关系但不属于另一关系的所有元组”“将两个关系必须按照某种条件串接成一个较大的关系”的操作依次是（）。1、并2、交3、积4、选择5、投影6、差7、连接

已知有：学生表Student(S#char(8),Snamechar(10),Ssexchar(2),Sageinteger,D#char(2),Sclasschar(6))中，若要在学生表中追加一个元组“学号为98030101的男同学张三，年龄为20，所属系别03，所在班级980301”，则可用（）。

20.JSP的执行肯定要经过Servlet才能执行。（）

20．下列语法错误的有（）（多选）（A）<%!intnum%>（B）<!--helloworld--!>（C）<%=5+3%>（D）<%@pageimport=”java.io.*;java.util.*”%>

2.下列选项中，（）可以准确地获取请求页面的一个文本框的输入（文本框的名称为name）.(A)request.getParameter（name）(B)request.getParameter（"name"）(C)request.getParameterValues(name)(D)request.getParameterValues("name")

无屈服阶段的塑性材料，以卸载后产生数值为0.2%塑性应变（残余应变）的应力值称为名义屈服极限（屈服强度）

二只50mL容量瓶，分别为(1)、(2)，在(1)号容量瓶中加入Cd2+未知液5.0mL，测得扩散电流为10μA，在(2)号容量瓶中加入Cd2+未知液5.0mL，再0.005mol/LCd2+标准溶液5.0mL，测得扩散电流为15μA，未知溶液中Cd2+的浓度是多少(mol/L)()

20．昨日は雪（　　　）。

2.TheXiaDynasty,thefirstinChinesehistory,wasestablishedinthe21stcenturyBC,headingthebeginningofaslavesocietyinChina.

ProfessorGoelhasamuchrosieroutlookonthefutureofartificialintelligencethan,say,ElonMusk,StephenHawking,BillGatesorSteveWozniak.20.WhatdoesProfessorGoelplantodo?

Althoughmanyofusmayfeelair-conditionersbringrelieffromhot,humidorpollutedoutsideair,theyposemanypotentialhealthhazards.Muchresearchhaslookedathowthemovementofairinsideaclosedenvironment---suchasanofficebuilding---canspreaddiseaseorexposepeopleinthebuildingtoharmfulchemicals.OneofthemorewidelypublicizeddangersisthatofLegionnaire’sdisease,whichwasfirstrecognizedinthe1970s.Thiswasfoundtohaveaffectedpeopleinbuildingswithair-conditioningsystemsinwhichwarmairpumpedoutofthesystem’coolingtowerswassomehowsuckedbackintotheairintake(通风口),inmostcasesduetopoordesign.Thewarmair,filledwithbacteria,wascombinedwithcooled,conditionedairandwasthencirculatedaroundvariouspartsofthebuilding.Studiesshowedthatevenpeopleoutsidesuchbuildingswereatriskiftheywalkedpastairexhaustpipes.Largeair-conditioningsystemsaddwatertotheairtheycirculatebymeansofhumidifiers(湿度调节器).Inoldersystems,thewaterusedforthisprocessiskeptinspecialreservoirs,thebottomsofwhichprovidebreedinggroundsforbacteriawhichcanfindtheirwayintotheventilation(通风)system.Therisktohumanhealthfromthissituationhasbeenhighlightedbythefactthattheimmunesystems(免疫系统)ofapproximatelyhalfofworkersinair-conditionedofficebuildingshavedevelopedtheabilitytofightofftheorganismsfoundatthebottomofsystemreservoirs.Butchemicalscalled“biocides”areaddedtoreservoirstomakethemgerm-free,andtheyaredangerousintheirownrightinsufficientquantities,astheyoftencontaincompoundsstronglylinkedtocancers.Finally,itshouldbepointedoutthattheartificialclimaticenvironmentcreatedbyair-conditionerscanalsoaffectus.Inanaturalenvironment,whetherindoororoutdoor,therearesmallvariationsintemperatureandhumidity.Indeed,thehumanbodyhaslongbeenaccustomedtothesenormalchanges.Inanair-conditionedlivingorworkingenvironment,however,bodytemperaturesremainwellunder37℃,ournormaltemperature.Thisleadstoaweakenedimmunesystemandthusgreaterexposuretodiseasessuchascoldsandflu.2.Intheoldair-conditionedsystems,bacteriafirstdevelop______.

ProfessorAshokGoelofGeorgiaTechdevelopedanartificiallyintelligentteachingassistanttohelphandletheenormousnumberofstudentquestionsintheonlineclass,Knowledge-BasedArtificialIntelligence.ThisonlinecourseisacorerequirementofGeorgiaTech’sonlineMasterofScienceinComputerScienceprogram.ProfessorGoelalreadyhadeightteachingassistants,butthatwasn’tenoughtodealwiththeoverwhelmingnumberofdailyquestionsfromstudents.Manystudentsdropoutofonlinecoursesbecauseofthelackofteachingsupport.Whenstudentsfeelisolatedorconfusedandreachoutwithquestionsthatgounanswered,theirmotivationtocontinuebeginstofade.ProfessorGoeldecidedtodosomethingtoremedythissituationandhissolutionwastocreateavirtualassistantnamedJillWatson,whichisbasedontheIBMWatsonplatform.GoelandhisteamdevelopedseveralversionsofJillWatsonbeforereleasinghertotheonlineforums.Atfirst,thevirtualassistantwasn’ttoogreat.ButGoelandhisteamsourcedtheonlinediscussionforumtofindallthe40,000questionsthathadeverbeenaskedsincetheclasswaslaunched.ThentheybegantofeedJillwiththequestionsandanswers.Aftersomeadjustmentsandsufficienttime,Jillwasabletoanswerthestudents’questionscorrectly97%ofthetime.Thevirtualassistantbecamesoadvancedandrealisticthatthestudentsdidn’tknowshewasacomputer.Thestudents,whowerestudyingartificialintelligence,wereinteractingwiththevirtualassistantandcouldn’ttellitapartfromarealhumanbeing.Goeldidn’tinformthemaboutJill’strueidentityuntilApril26.Thestudentswereactuallyverypositiveabouttheexperience.ThegoalofProfessorGoel’svirtualassistantnextyearistotakeoveranswering40%ofallthequestionsposedbystudentsontheonlineforum.ThenameJillWatsonwill,ofcourse,changetosomethingelsenextsemester.ProfessorGoelhasamuchrosieroutlookonthefutureofartificialintelligencethan,say,ElonMusk,StephenHawking,BillGatesorSteveWozniak.20.WhatdoesProfessorGoelplantodonextwithJillWatson?