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人呼出的气体中成分最多的是什么?

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氮气

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TheImportanceofGoodCommunications Effectivecommunicationisessentialforallorganizations.Itlinkstheactivitiesofthevariouspartsoftheorganizationandensuresthateveryoneisworkingtowardsacommongoal.Itisalsoextremelyimportantformotivatingemployees.Staffneedtoknowhowtheyaregettingon,whattheyaredoingrightandinwhichareastheycouldimprove.Workingalonecanbeextremelydifficultanditismucheasierifsomeonetakesaninterestandprovidessupport.Employeesneedtounderstandwhytheirjobisimportantandhowitcontributestotheoverallsuccessofthefirm.Personalcommunicationshouldalsoincludetargetsetting.Peopleusuallyrespondwelltogoals,providedtheseareagreedbetweenthemanagerandsubordinateandnotimposed. However,firmsoftenhavecommunicationproblemsthatcanunderminetheirperformance.Inmanycases,theseproblemsoccurbecausemessagesarepassedoninaninappropriateway.Thereare,ofcourse,severalwaysofconveyinginformationtoothersintheorganizationwhichincludespeakingtothemdirectly,e-mailing,telephoningorsendingamemo.Themostappropriatemethoddependsonwhatexactlyitisyouarecommunicating.Forexample,anythingthatisparticularlysensitiveorconfidential,suchasanemployee'sappraisal,shouldbedoneface-to-face. Oneofthemainproblemsforseniorexecutivesisthattheydonothavethetimeorresourcesneededtocommunicateeffectively.Inlargecompanies,forexample,itisimpossibleforseniormanagerstomeetanddiscussprogresswitheachemployeeindividually.Obviouslythistaskcanbedelegatedbutatthecostofcreatingagapbetweenseniormanagementandstaff.Asaresult,managersareoftenforcedtouseothermethodsofcommunication,likememosornotes,eveniftheyknowthesearenotnecessarilythemostsuitablemeansofpassingonmessages. Theuseoftechnology,suchase-mail,mobilephonesandnetworksystems,isspeedingupcommunicationimmensely.However,thisdoesnotmeanthatmoreinvestmentintechnologyautomaticallyprovesbeneficial:systemscanbecomeoutdatedoremployeesmaylackappropriatetraining.Therearemanycommunicationstoolsnowavailablebutafirmcannotaffordallofthem.Evenifitcould,itdoesnotactuallyneedthemall.Thepotentialgainsmustbeweighedupagainstthecosts,andfirmsshouldrealizethatmorecommunicationdoesnotnecessarilymeanbettercommunication." Asthenumberofpeopleinvolvedinanorganizationincrease,theuseofwrittencommunicationrisesevenfaster.Insteadofaquickconversationtosortsomethingoutnumerousmessagescanbepassedbackwardsandforwards.Thiscanleadtoatremendousamountofpaperworkandisoftenlesseffectivethanface-to-facecommunication.Whenyouareactuallytalkingtosomeoneyoucandiscussthingsuntilyouarehappythattheyhaveunderstoodandfeedbackisimmediate.Withwrittenmessages,however,youareneverquitesurehowitwillbereceivedwhatyouthinkyouhavesaidandwhattheotherpersonthinksyouhavesaidcanbeverydifferent. Theamountofwritteninformationgeneratedinlargeorganizationstodaycanleadtocommunicationoverload.Somuchinformationisgatheredthatitgetsinthewayofmakingdecisions.Takealookattheaveragemanager'sdeskandyouwillseetheproblem--itisoftencoveredwithletters,reportsandmemos.Thisoverloadcanleadtoinefficiencies.Forexample,managersmaynotbeabletofindtheinformationtheywantwhentheyneedit.Communicationisalsobecomingmoredifficultwiththechangesoccurringinemploymentpatterns.Withmorepeopleworkingpart-timeandworkingathome,managingcommunicationisbecomingincreasinglycomplex. 1.InthefirstparagraphthewriterrecommendsthatcommunicationwithstaffshouldincludeA.somefeedbackontheirjobperformance. B.anexplanationofhowcompanytargetshavebeenset. C.informationonpromotionprospectswithinthecompany. D.anindicationofwhichdutiestheycanexpectassistancewith.areastheycouldimprove 2.Accordingtothewriter,thebestwayofachievingeffectivecommunicationistoA.adaptthemessagetosuitaparticularaudience. B.makethecontentofmessagesbriefanddirect. C.selectthemostsuitablemeansofconveyingaparticularmessage. D.ensurethatinformationistargetedattheappropriategroupofpeople. 3.Whatdoesthewritersayaboutthecommunicationoptionsavailabletoseniormanagers?A.Sendingmemostostaffisoneofthemostefficientmethods. B.Itisimportanttofindthetimetodiscusscertainmatterswithstaff. C.Theyshouldincreasetherangeofoptionsthattheyuse. D.Gettingjuniormanagerstotalktostaffcancreatedifferentproblems. 4.Whatadviceisgivenaboutthecommunicationtoolsmadeavailablebytechnology?A.Aimtolimitstaffuseofcertaincommunicationtools. B.Evaluatethemintermsoftheexpenditureinvolved. C.Selectthemonthebasisofthefacilitiestheyoffer. D.Encouragemorestafftoattendtrainingcoursesintheiruse. 5.Accordingtothewriter,aproblemwithwrittencommunicationisthatA.themessagecanbeinterpreteddifferentlytowhatwasintended. B.itcanbeeasyforpeopletoignorethecontentsofawrittenmessage. C.mostpeoplearemorecomfortablewithface-to-facecommunication. D.itispossibleforcorrespondencetogetlostwithinalargeorganization. 6.Accordingtothearticle,whatistheeffectofreceivinglargeamountsofwritteninformation?A.Itiscounter-productive." B.Itcausesconflictinacompany. C.Itleadstochangesinworkpatterns. D.Itmakesthemainpointsmoredifficulttoidentify.
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练习次数:32次
1There'sadimmerswitchinsidethesunthatcausesitsbrightnesstoriseandfallontimescalesofaround100,000years-exactlythesameperiodasbetweeniceagesonEarth.Sosaysaphysicistwhohascreatedacomputermodelofourstar'score. 2RobertEhrlichofGeorgeMasonUniversityinFairfax,Virginia,modelledtheeffectoftemperaturefluctuationsinthesun'sinterior.Accordingtothestandardview,thetemperatureofthesun'scoreisheldconstantbytheopposingpressuresofgravityandnuclearfusion.However,Ehrlichbelievedthatslightvariationsshouldbepossible. 3HetookashisstartingpointtheworkofAttilaGrandpierreoftheKonkolyObservatoryoftheHungarianAcademyofSciences.In2005,Grandpierreandacollaborator,Gáborágoston,calculatedthatmagneticfieldsinthesun'scorecouldproducesmallinstabilitiesinthesolarplasma.Theseinstabilitieswouldinducelocalisedoscillationsintemperature. 4Ehrlich'smodelshowsthatwhilstmostoftheseoscillationscanceleachotherout,somereinforceoneanotherandbecomelong-livedtemperaturevariations.Thefavouredfrequenciesallowthesun'scoretemperaturetooscillatearounditsaveragetemperatureof13.6millionkelvinincycleslastingeither100,000or41,000years.Ehrlichsaysthatrandominteractionswithinthesun'smagneticfieldcouldflipthefluctuationsfromonecyclelengthtotheother. 5ThesetwotimescalesareinstantlyrecognisabletoanyonefamiliarwithEarth'siceages:forthepastmillionyears,iceageshaveoccurredroughlyevery100,000years.Beforethat,theyoccurredroughlyevery41,000years. 6MostscientistsbelievethattheiceagesaretheresultofsubtlechangesinEarth'sorbit,knownastheMilankovitchcycles.OnesuchcycledescribesthewayEarth'sorbitgraduallychangesshapefromacircletoaslightellipseandbackagainroughlyevery100,000years.ThetheorysaysthisalterstheamountofsolarradiationthatEarthreceives,triggeringtheiceages.However,apersistentproblemwiththistheoryhasbeenitsinabilitytoexplainwhytheiceageschangedfrequencyamillionyearsago. 7"InMilankovitch,thereiscertainlynogoodideawhythefrequencyshouldchangefromonetoanother,"saysNeilEdwards,aclimatologistattheOpenUniversityinMiltonKeynes,UK.NoristhetransitionproblemtheonlyonetheMilankovitchtheoryfaces.EhrlichandothercriticsclaimthatthetemperaturevariationscausedbyMilankovitchcyclesaresimplynotbigenoughtodriveiceages. 8However,EdwardsbelievesthesmallchangesinsolarheatingproducedbyMilankovitchcyclesarethenamplifiedbyfeedbackmechanismsonEarth.Forexample,ifseaicebeginstoformbecauseofaslightcooling,carbondioxidethatwouldotherwisehavefounditswayintotheatmosphereaspartofthecarboncycleislockedintotheice.ThatweakensthegreenhouseeffectandEarthgrowsevencolder. 9AccordingtoEdwards,thereisnolackofsuchmechanisms."Ifyouaddtheireffectstogether,thereismorethanenoughfeedbacktomakeMilankovitchwork,"hesays."Theproblemnowisidentifyingwhichmechanismsareatwork."ThisiswhyscientistslikeEdwardsarenotyetreadytogiveuponthecurrenttheory."Milankovitchcyclesgiveusiceagesroughlywhenweobservethemtohappen.Wecancalculatewhereweareinthecycleandcompareitwithobservation,"hesays."Ican'tseeanywayoftesting[Ehrlich's]ideatoseewhereweareinthetemperatureoscillation." 10Ehrlichconcedesthis."Ifthereisawaytotestthistheoryonthesun,Ican'tthinkofonethatispractical,"hesays.That'sbecausevariationover41,000to100,000yearsistoogradualtobeobserved.However,theremaybeawaytotestitinotherstars:reddwarfs.Theircoresaremuchsmallerthanthatofthesun,andsoEhrlichbelievesthattheoscillationperiodscouldbeshortenoughtobeobserved.Hehasyettocalculatethepreciseperiodortheextentofvariationinbrightnesstobeexpected. 11NigelWeiss,asolarphysicistattheUniversityofCambridge,isfarfromconvinced.HedescribesEhrlich'sclaimsas"utterlyimplausible".EhrlichcountersthatWeiss'sopinionisbasedonthestandardsolarmodel,whichfailstotakeintoaccountthemagneticinstabilitiesthatcausethetemperaturefluctuations. 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Inboxes5-9onyouranswersheetwrite TRUEifthestatementistrueaccordingtothepassage FALSEifthestatementisfalseaccordingtothepassage NOTGIVENiftheinformationisnotgiveninthepassage 5.Theiceageschangedfrequencyfrom100,000to41,000yearsamillionyearsago. 6.ThesoleproblemthattheMilankovitchtheorycannotsolveistoexplainwhytheiceagefrequencyshouldshiftfromonetoanother. 7.Carbondioxidecanbelockedartificiallyintoseaicetoeliminatethegreenhouseeffect. 8.SomescientistsarenotreadytogiveuptheMilankovitchtheorythoughtheyhaven'tfiguredoutwhichmechanismsamplifythechangesinsolarheating. 9.BothEdwardsandEhrlichbelievethatthereisnopracticalwaytotestwhenthesolartemperatureoscillationbeginsandwhenends. Questions10-14 Completethenotesbelow. ChooseonesuitablewordfromtheReadingPassageaboveforeachanswer. Writeyouranswersinboxes10-14onyouranswersheet. Thestandardviewassumesthattheopposingpressuresofgravityandnuclearfusionsholdthetemperature...10...inthesun'sinterior,buttheslightchangesintheearth's...11...alterthetemperatureontheearthandcauseiceagesevery100,000years.ABritishscientist,however,challengesthisviewbyclaimingthattheinternalsolarmagnetic...12...caninducethetemperatureoscillationsinthesun'sinterior.Thesun'scoretemperatureoscillatesarounditsaveragetemperaturein...13...lastingeither100,000or41,000years.Andthe...14...interactionswithinthesun'smagneticfieldcouldflipthefluctuationsfromonecyclelengthtotheother,whichexplainswhytheiceageschangedfrequencyamillionyearsago.
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