成本会计工作中分散在单位内部各部门和所属单位分别进行的工作方式是（）

按照马克思的理论成本，产品成本是指产品价值中的（）。

人与自然相处时应承担的重要责任是（）。

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.Theauthormostprobablywantsthereaderstotreatbiocideswithanattitudeof_.

49.Whatdowelearnaboutthemedicalcommunity?A)Theynowhaveastronginterestinresearchonaging.B)Theydifferfromtheacademiccirclesintheirviewonaging.C)Theycancontributetopeople’shealthonlytoalimitedextent.D)Theyhavewaystointerveneinpeople'sagingprocess.

论文选题的要求

实用放大电路多引入深度负反馈，若()可认为电路引入负反馈为深度负反馈。

学生公寓内容易引起火灾的因素（）

悲剧竞赛设立之后，雅典正式确定在冬季的乡村酒神节中增加喜剧竞赛项目。

下列语句中用字正确的一项是（）