已知H3PO4的pKa1=2.12,pKa2=7.20,pKa3=12.36。今有一磷酸盐溶液的pH=12.78,则其主要存在形式是()

欲配制pH为3的缓冲溶液，应选择的弱酸及其弱酸盐是（）

每升KMnO4标准溶液含3.1601g KMnO4，此标准溶液对Fe2+的滴定度为(    ) g/mL。  (已知高锰酸钾摩尔质量为158g/mol，铁的摩尔质量为55.85g/mol)  

已知H3PO4的pKa1=2.12,pKa2=7.20,pKa3=12.36。今有一磷酸盐溶液的pH=4.78,则其主要存在形式是()

3.056数据为几位有效数字?()

某企业于年初存入银行50000元，假定年利息率为12%，每年复利两次。已知（F/P，6%，5）=1.3382，（F/P，6%，10）=1.7908，（F/P，12%，5）=1.7623，（F/P，12%，10）=3.1058，则第5年年末的本利和为（　　）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

12.运用JSP技术进行开发可以将内容的生成和显示相分离。（）

3．当request对象获取客户端提交的汉字字符时，会出现乱码问题，解决方式是改变编码格式为UTF8。（）

12．（）动作用于嵌入现有的Bean（A）include（B）useBean（C）setProperty（D）getProperty

3.使用response对象进行重定向时，使用的是（）方法选一项(A)getAttribute(B)setContentType(C)sendRedirect(D)setAttribute

3．どちら（　）あなたの本ですか。

12．「２時から会議だから、（　　　　）行きましょうか。」　　　[そうですね。」

3.Generally,peopleinsouthChinalikenoodles,whilepeopleinthenorthpreferrice.

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.3.Thefactthatabouthalfofworkersdevelopedtheabilitytofightoffthebacteriamay__.