summary例子和答案

TheDevelopmentofWritingFewpeoplewoulddisagreewiththebeliefthatprimitivemanlearnedtospeaklongbeforehedevelopedasystemofwriting.Butwhilehisearlyspokenlanguagemayhavebeennothingmorethanafewsounds,earlymancouldtransmitmessagesacrossdistancesbymeansofsignalsfromdrums,smokeandfire.Itwasprobablyadesiretorecordmessagesthatledtothedevelopmentofalphabets.Forearlyman,whocouldspeakandwhocouldsendmessages,couldnotputthosemessagesintopermanentform.Thedesiretohavepermanentrecordsmaynotbeeasilyunderstoodintoday’sworldwhereelectronicsciencehasmadediskandtaperecordingscommonplace.Ifearlymanwantedtoleaverecordsofpasteventstoremindhimofgoodtimesandbad,hehadtodependonhismemory,andonprimitivemarkingssuchaspilesofstones,cuttingsonsticks,etc.Thelimitationsofthissystemledearlymantoturntorockdrawingsfortheexpressionofsophisticatedideas.Thisformofwritingdependedonpicturestoconveyideas,andalthoughmoreadvancedthanpreviousdevelopments,itwasstilltoolimitedformantobeentirelysatisfied.Manfinallywasabletodevelopasystemofpicturewritingthatassociatedsymbolsandsound.Thissystem,whichwasoriginatedbytheearlySumeriansandtheEgyptiansmorethan3,000.,isbasedonthesameprinciplethatwesuetodayinmostworldalphabets.Itwasabout1,000.thatthePhoenicianstookthecomplicatedpicturealphabetsoftheEgyptiansandsimplifiedthenintoabout30symbols,eachonestandingforaconsonantsound.Finally,theancientGreeks,about800.,refinedthisPhoenicianalphabetandaddedsignsforvowelsounds.ThealphabetusedinEnglish,andinmanyotherworldlanguages,iscalledtheRomanalphabetbecauseitwasdevelopedbytheRomanswhohadtakenmostofitfromanotherItalicpeople,theEtruscan,who,intheirturn,hadlearneditfromtheancientGreeks.LettersonancientmonumentsinRomeprovethattheRomanalphabet,thesamealphabetusedtoday,hadbeenperfectedby.114.SecrettoLongevityLiesinGenes,StudyFindsTueJun11,5:16PMETbyMaggieFox,HealthandSciencesCorrespondentWASHINGTON(Reuters)Wanttolivetobe100?Pickoldgrandparents.It’sanoldirony,butresearcherssaidonTuesdaytheyhadshownthisisremarkablytruewhenitcomestosurvivingintooldage,andtheybelieveaclusterofjustafewgenesmayberesponsible.Theyhavesetupacompanythatstudiescentenarianstoseeifthegenericsecrettolivingalongandhealthylifemayresultindrugsthatcanpreventthediseasesofaging,suchasAlzheimer’sandheartdisease.Itisn’treallythatobvious,Dr.ThomasPerls,wholedthestudy,saidinatelephoneinterview.Itisn’toldagethatrunsinfamilies.It’sexceptionaloldagethatrunsinfamilies.Wethinkthismaybeahandfulofgenesthatcouldbeplayingreallysubstantialrolesintheabilitytogettoveryoldage,muchofitingoodhealth.Perl’steamatHarvardUniversityandBethIsraelDeaconessMedicalSchoolstudied444families,includingmorethan2,000relativesofpeoplewholiveto100.DemographerJohnWilmothoftheUniversityofCaliforniaBerkeleycomparedthisdatatothe1900censusandtheSocialSecurityAdministrationdatabase.Femalesiblingshaddeathratesatallagesataboutone-halfthenationallevel,theywroteintheirreport,publishedinthisweekissueoftheProceedingsoftheNationalAcademyofSciences.Malesiblingsofcentenarianswereatleast17timesaslikelytoattainage100themselves,whilefemalesiblingswereatleasteighttimesaslikely.Perlsisnotinterestedinextendinglifeatanycost.WHOWANTSTOGETTHATOLD,ANYWAY?Peoplemightthink,whowantstoliveto100anyway?becausepeoplegettheideathattheolderyouget,thesickeryouget.Buthisstudyfoundjusttheopposite.YoucangetAlzheimer,stroke,cancerinyour60sand70sandexpecttoliveanother30,40years.EarlierworkhasshownmanyofthesepeoplesharesimilaritiesintheirDNA,especiallyonchromosome4.Perlshopeshiscompany,Centagenetixcanhomeinontheimportantgenesandperhapsmakediscoveriesthatwillleadtodrugsthatcanstaveoffdisease.Discoveringthesegeneswillleadtounderstandingthebiochemicalpathwaysthatthosegenesaffect,hesaid.Myhopeisthatthatwouldhelpalotofotherpeopleagemoreslowlyanddelayand,mygoodnessevenescape,somethinglikeAlzheimer.Whichgenesyoudonothavemaybeasimportantasthoseyoudo,Perlssaid.Forinstance,hefoundthe100-year-oldswereveryunlikelytohaveaversionofagenecalledAPOE-4,whichisassociatedwithhighcholesterolandAlzheimer.Environmentdidnotseemtobetooimportanttothosewholivedtobe100.CensusBureaudatashowedtheyweremorelikelytobepoorandpoorlyeducated?somethingnotusuallyassociatedwitholdage.Butformostofus,environmentandbehavioriskey.Ithinktheaveragesetofgenesgetsustoourmid-tolate-80s,saidPerls,ageriatricianwhonowworksatBostonMedicalCenter.IbasethisontwinstudiesandonSeventhDayAdventists,whohavealifeexpectancyof87years,whodoeverythingright。Theysmoke,theyarelean,theyarevegetarian,theyexerciseandasaresulttheylive10yearslongerthantherestofus.Thatbasicallytellsuswhatourgenesarecapableof.Buttolivetheextra15,20yearsbeyondthat,Isuspectgenesareplayingagreaterrole.SoThatNobodyHasToGoToSchoolIfTheyDon'tWantbyTobyRogerSipherAdeclineinstandardizedtestscoresisbutthemostrecentindicatorthatAmericaneducationisintrouble.Onereasonforthecrisisisthatpresentmandatory-attendancelawsforcemanytoattendschoolwhohavenowishtobethere.Suchchildrenhavelittledesiretolearnandaresoantagonistictoschoolthatneithertheynormorehighlymotivatedstudentsreceivethequalityeducationtha