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阅读下面的短文文章中有5处空白文章后面有6组文字请根据文章的内容选择5组文字将其分别放回文章原有位置
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阅读下面的短文文章中有5处空白文章后面有6组文字请根据文章的内容选择5组文字将其分别放回文章原有位置
阅读下面的短文文章有5处空白文章后面有6组文字请根据文章的内容选择5组文字将其分别放回文章原有位置以
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阅读下面的短文文章中有5处空白文章后面有6组文字请根据文章的内容选择5组文字将其分别放回文章原有位置
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阅读下面的短文文章有5处空白文章后面有6组文字请根据文章的内容选择5组文字将其分别放回文章原有位置以
阅读下面的短文文章中有5处空白文章后面有6组文字请根据文章的内容选择5组文字将其分别放回文章原有位置
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Assoonaswearrivedatthecampsitewe{{U}}erected{{/U}}ourtent.
AmericansDecrease IncreasinglyhistoriansareblamingdiseasesimportedfromtheOldWorldforthestaggeringdisparity不同betweentheindigenous本土的populationofAmericain1492—newestimatesofwhichsoarashighas100millionorapproximatelyone-sixthofthehumanraceatthattime—andthefewmillionfull-bloodedNativeAmericansaliveattheendofthenineteenthcentury.Thereisnodoubtthatchronicdiseasewasanimportantfactorintheprecipitous险峻的declineanditishighlyprobablethatthegreatestkillerwasepidemicdiseaseespeciallyasmanifestedinvirgin-soil处女地epidemics. Virgin-soilepidemicsarethoseinwhichthepopulationsatriskhavehadnopreviouscontactwiththediseasesthatstrikethemandarethereforeimmunologically免疫学的almostdefenseless.Thatvirgin-soilepidemicswereimportantinAmericanhistoryisstronglyindicatedbyevidencethatanumberofdangerousmaladies病—smallpoxmeasles麻疹malaria疟病yellowfeverandundoubtedlyseveralmore—wereunknowninthepre-ColumbianNewWorld.TheeffectsoftheirsuddenintroductionaredemonstratedintheearlychroniclesofAmericawhichcontainreportsofhorrendous可怕的epidemicsandsteeppopulationdeclinesconfirmedinmanycasesbyrecentequantitativeanalysesofSpanishtributerecordsandothersources.TheevidenceprovidedbythedocumentsofBritishandFrenchcoloniesisnotasdefinitivebecausetheconquerorsofthoseareasdidnotestablishpermanentsettlementsandbegintokeepcontinuousrecordsuntiltheseventiethcenturybywhichtimetheworstepidemicshadprobablyalreadytakenplace.FurthermoretheBritishtendedtodrivethenativepopulationsawayratherthanenslavingthemastheSpaniardsdidsothattheepidemicsofBritishAmericaoccurredbeyondtherangeofcolonistsdirectobservation. EvensothesurvivingrecordsofNorthAmericadocontainreferencestodeadlyepidemicsamongtheindigenouspopulation.In1616—1619anepidemicpossiblyofbubonicorpneumonic肺的plague瘟疫sweptcoastalNewEnglandkillingasmanyasnineoutoften.Duringthe1630’’ssmall-poxthediseasemostfataltotheNativeAmericanpeopleeliminatedhalfthepopulationoftheHuronandIroquoisconfederations.Inthe1820’’sfeverdevastatedthepeopleoftheCoulumbiaRiverareakillingeightoutoftenofthem. UnfortunatelythedocumentationoftheseandotherepidemicsisslightandfrequentlyunreliableanditisnecessarytosupplementwhatlittlewedoknowwithevidencefromrecentepidemicsamongNativeAmericans.Forexamplein1952anoutbreakofmeaslesamongtheNativeAmericaninhabitantsofUngavaBay.Quebecaffected99percentofthepopulationandkilled7percenteventhoughsomehadthebenefitofmodernmedicine.Casessuchasthisdemonstratethatevendiseasesthatarenotnormallyfatalcanhavedevastatingconsequenceswhentheystrikeanimmunologicallydefenselesscommunity. WhichofthefollowingcanbeinferredfromthepassageabouttheNativeAmericaninhabitantsofUngavaBay?
OnAntibodies Substancesforeigntothebodysuchasdisease-causingbacteriaandvirusesandotherinfectiousagentsarerecognizedbythebodysimmunesystemasinvaders.Ournaturaldefensesagainsttheseinfectiousagentsareantibodiesproteinsthatseekouttheantigens抗原andhelpdestroythem. Antibodieshavetwoveryusefulcharacteristics.Firsttheyareextremelyspecific;thatiseachantibodybindstoandattacksoneparticularantigen.Secondsomeantibodiesonceactivatedbytheoccurrenceofadiseasecontinuetoconferresistanceagainstthatdisease.Classicexamplearetheantibodiestothechildhooddiseasesofchickenpox水痘andmeasles. Thesecondcharacteristicofantibodiesmakesitpossibletodevelopvaccines.Avaccine痘苗isapreparationofkilledorweakenedbacteriaorvirusesthatwhenintroducedintothebodystimulatestheproductionofantibodiesagainsttheantigensitcontains. Itisthefirsttraitofantibodiestheirspecificitythatmakesmonoclonalantibodytechnologysovaluable.Notonlycanantibodiesbeusedtherapeutically在治疗上toprotectagainstdisease;theycanalsohelpto.diagnoseawidevarietyofillnessesandcandetectthepresenceofdrugsviralandbacterialproductsandotherunusualorabnormalsubstancesintheblood. Givensuchadiversityofusesforthesediseased-fightingsubstancestheirproductioninpurequantitieshaslongbeenthefocusofscientificinvestigation.Theconventionalmethodwastoinjectalaboratoryanimalwithanantigenandthenafterantibodieshadbeenformedcollectthoseantibodiesfromthebloodserum血清Antibodycontainingbloodserumiscalledantiserum抗血清.Therearetwoproblemswiththismethod:Ityieldsantiserumthatcontainsundesiredsubstancesanditprovidesaverysmallamountofusableantibody. Monoclonalantibodytechnologyallowsustoproducelargeamountsofpureantibodies.inthefollowingway:wecanobtaincellsthatproduceantibodiesnaturally;wealsohaveavailableaclassofcellsthatcangrowcontinuallyincellculture培养.Ifweformahybrid混血儿thatcombinesthecharacteristicofimmortality永生withtheabilitytoproducethedesiredsubstancewewouldhaveineffectafactorytoproduceantibodiesthatworkaroundtheclock. Inmonoclonalantibodytechnologytumorcellsthatcanreplicate重复endlesslyarefusedwithmammaliancellsthatproduceanantibody.Theresultofthiscellfusionisahybridoma杂交瘤whichwillcontinuallyproduceantibodies.Theseantibodiesarecalledmonoclonalbecausetheycomefromonlyonetypeofcellthehybridomacell;antibodiesproducedbyconventionalmethodsontheotherhandarederivedfrompreparationscontainingmanykindsofcellsandhencearecalledpolyclonal.Anexampleofhowmonoclonalantibodiesarederivedisdescribedbelow. Amyelomaisatumorofthebonemarrow骨髓thatcanbeadaptedtogrowpermanendyincellculture.Whenmyelomacellswerefusedwithantibody-producingmammalianspleencellsitwasfoundthattheresultinghybridcellsorhybridomasproducedlargeamountsofmonoclonal骨髓瘤antibody.Thisproductofcellfusioncombinedthedesiredqualitiesofthetwodifferenttypesofcells:theabilitytogrowcontinuallyandtheabilitytoproducelargeamountsofpureantibody. Becauseselectedhybridcellsproduceonlyonespecificantibodytheyaremorepurethanthepolyclonalantibodiesproducedbyconventionaltechniques.Theyarepotentiallymoreeffectivethanconventionaldrugsinfightingdiseasesincedrugsattacknotonlytheforeignsubstancebutthebody’sowncellsaswellsometimesproducingundesirablesideeffectssuchasnausea恶心andallergicreactions.Monoclonalantibodiesattackthetargetmoleculeandonlythetargetmoleculewithnoorgreatlydiminishedsideeffects. Allthefollowingstatementsaboutantibodiesaretrueexcept______.
CigarsInstead? Smokingoneortwocigarsadaydoublestheriskofcancersoftheliptonguemouthandthroataccordingtoagovernmentstudy. DailycigarsalsoincreasetheriskoflungcancerandcanceroftheesophagusandincreasetheriskofcancerofthelarynxvoiceboxsixfoldsayresearchersattheNationalCancerInstituteinBethesdaMaryland. Inadditionthereportrevealedthatsmokingthreeorfourcigarsadayincreasedtheriskoforalcancerto8.5timestheriskfornonsmokersandtheriskofesophagealcancerbyfourtimestheriskofnonsmokers. ThehealtheffectsofsmokingcigarsisoneofeightsectionsofthearticleCigars:HealthEffectsandTrends.Theresearchersreportthatcomparedwithacigarettealargecigaremitsupto90timesasmuchcarcinogenictobacco-specificnitrosamines ThisarticleprovidesclearandinvaluableinformationaboutthedisturbingincreaseincigaruseandthesignificantpublichealthconsequencesforthecountrysaidDr.RichardKlausnerdirectoroftheNationalCancerInstituteinastatement. Thedataareclear-theharmfulsubstancesandcarcinogensincigarsmokelikecigarettesareassociatedwiththeincreasedrisksofseveralkindsofcancersaswellasheartandlungdiseasesheadded.Inotherwordscigarsarenotsafealternativestocigarettesandmaybeaddictive. Tothoseindividualswhomaybethinkingaboutsmokingcigarsouradvicesis—don’’t.TothosecurrentlysmokingcigarsquittingistheonlywaytoeliminatecompletelythecancerheartandlungdiseaseriskswarnedKlausner. AccordingtoaNationalCancerInstitutepressreleasetherehaven’’tbeenanystudiesonthehealtheffectsonnonsmokersatcigarsocialeventsbut...asignificantbodyofevidenceclearlydemonstratesanincreasedlungcancerriskfromsecondhandsmoke. Inthepassagehowmanycancersarementionedinrelationtosmokingcigarsdaily?
Theaudienceatthemusichall{{U}}applauded{{/U}}enthusiasticallyafterthepianosolo.
Thetraincametoanabruptstopmakinguswonderwherewewere.
Dyslexia Asmanyas20%ofallchildrenintheUnitedStatessufferfromsomeformofthelearningdisorder2calleddyslexia. Expertsondyslexiasaythattheproblemisnotadisease.Theysaythatpersonswithdyslexiauseinformationinadifferentway.Oneoftheworldsgreatthinkersandscientists.AlbertEinsteinwasdyslexic.Einsteinsaidthatheneverthoughtinwordsthewaythatmostpeopledo.Hesaidthathethoughtinpicturesinstead. TheAmericaninventorThomasEdisonwasalsodyslexic.DyslexiafirstwasrecognizedinEuropeandtheUnitedStatesmorethan80yearsago.Manyyearspassedbeforedoctorsdiscoveredthatpersonswiththedisorderwerenotmentallyslowordisabled.Thedoctorsfoundthatthebrainsofpersonswithdyslexiaaredifferent. Inmostpeopletheleftsideofthebrain—thepartthatcontrolslanguageislargerthantherightside.Inpersonswithdyslexiatherightsideofthebrainisbigger.Doctorsarenotsurewhatcausesthisdifference.Howeverresearchhasshownthatdyslexiaismorecommoninmalesthaninfemalesanditisfoundmoreofteninpersonswhoarelefthanded4.Nooneknowsthecauseofdyslexiabutsomescientistsbelievethatitmayresultfromchemicalchangesinababy’’sbodylongbeforeitisborn.Theyaretryingtofindwaystoteachpersonswithdyslexia.Dyslexicpersonsthinkdifferentlyandneedspecialkindsofteachinghelp.Aftertheyhavesolvedtheirproblemswithlanguagetheyoftenshowthemselvestobeespeciallyintelligentorcreative. ThefirstcasesofdyslexiainEuropewerediscoveredlessthanacenturyago.
Language Whenmostofusthinkaboutlanguagewethinkfirstaboutwords.Thusthehardestpartoflearningaforeignlanguagemayseemtobememorizing【51】vocabulary;whenweobserveachildfirstacquiringspeechwetalkofhisprogress【52】amatteroflearningnewwords.Wearealso【53】tofeelthattheadultspeakerwiththelargestvocabularyhasthebest【54】ofEnglish.Tothink【55】alanguageasjustastockofwordsis【56】quitewrong.Wordsalonedonot【57】alanguage;agrammaris【58】tocombinetheminsomeintelligibleway.Moreoverwordsarerelativelyeasytolearnandindeedallofusgo【59】learningthemallour【60】.Theyarealsothe【61】stablepartoflanguage.Wordscomeinto【62】changetheirpronunciationsandmeaningsanddisappearcompletelyallwithcomparativeease.Yetitistruethatthe【63】isfocusoflanguage.Itisinwords【64】soundsandmeaningsinterlocktoallowusto【65】withoneanotheranditiswordsthatwearrangetogethertomakesentencesconversationsanddiscourseofallkinds.Thuswehaveaparadoxinthatthemostshort-livedpartoflanguageisalsothecentrewheremeaningpronunciationandgrammarcometogether.
Dyslexia Asmanyas20%ofallchildrenintheUnitedStatessufferfromsomeformofthelearningdisorder2calleddyslexia. Expertsondyslexiasaythattheproblemisnotadisease.Theysaythatpersonswithdyslexiauseinformationinadifferentway.Oneoftheworldsgreatthinkersandscientists.AlbertEinsteinwasdyslexic.Einsteinsaidthatheneverthoughtinwordsthewaythatmostpeopledo.Hesaidthathethoughtinpicturesinstead. TheAmericaninventorThomasEdisonwasalsodyslexic.DyslexiafirstwasrecognizedinEuropeandtheUnitedStatesmorethan80yearsago.Manyyearspassedbeforedoctorsdiscoveredthatpersonswiththedisorderwerenotmentallyslowordisabled.Thedoctorsfoundthatthebrainsofpersonswithdyslexiaaredifferent. Inmostpeopletheleftsideofthebrain—thepartthatcontrolslanguageislargerthantherightside.Inpersonswithdyslexiatherightsideofthebrainisbigger.Doctorsarenotsurewhatcausesthisdifference.Howeverresearchhasshownthatdyslexiaismorecommoninmalesthaninfemalesanditisfoundmoreofteninpersonswhoarelefthanded4.Nooneknowsthecauseofdyslexiabutsomescientistsbelievethatitmayresultfromchemicalchangesinababy’’sbodylongbeforeitisborn.Theyaretryingtofindwaystoteachpersonswithdyslexia.Dyslexicpersonsthinkdifferentlyandneedspecialkindsofteachinghelp.Aftertheyhavesolvedtheirproblemswithlanguagetheyoftenshowthemselvestobeespeciallyintelligentorcreative. Dyslexicpeopleoftenturnouttobeintelligentorcreativeonetheyhavelearnedtohandlelanguageproperly.
Thegovernmentwouldnotdaretoimposetaxesonsuchnecessitiesasbreadormilk.
Language Whenmostofusthinkaboutlanguagewethinkfirstaboutwords.Thusthehardestpartoflearningaforeignlanguagemayseemtobememorizing【51】vocabulary;whenweobserveachildfirstacquiringspeechwetalkofhisprogress【52】amatteroflearningnewwords.Wearealso【53】tofeelthattheadultspeakerwiththelargestvocabularyhasthebest【54】ofEnglish.Tothink【55】alanguageasjustastockofwordsis【56】quitewrong.Wordsalonedonot【57】alanguage;agrammaris【58】tocombinetheminsomeintelligibleway.Moreoverwordsarerelativelyeasytolearnandindeedallofusgo【59】learningthemallour【60】.Theyarealsothe【61】stablepartoflanguage.Wordscomeinto【62】changetheirpronunciationsandmeaningsanddisappearcompletelyallwithcomparativeease.Yetitistruethatthe【63】isfocusoflanguage.Itisinwords【64】soundsandmeaningsinterlocktoallowusto【65】withoneanotheranditiswordsthatwearrangetogethertomakesentencesconversationsanddiscourseofallkinds.Thuswehaveaparadoxinthatthemostshort-livedpartoflanguageisalsothecentrewheremeaningpronunciationandgrammarcometogether.
Theyjoinedthearmywillingly.
Language Whenmostofusthinkaboutlanguagewethinkfirstaboutwords.Thusthehardestpartoflearningaforeignlanguagemayseemtobememorizing【51】vocabulary;whenweobserveachildfirstacquiringspeechwetalkofhisprogress【52】amatteroflearningnewwords.Wearealso【53】tofeelthattheadultspeakerwiththelargestvocabularyhasthebest【54】ofEnglish.Tothink【55】alanguageasjustastockofwordsis【56】quitewrong.Wordsalonedonot【57】alanguage;agrammaris【58】tocombinetheminsomeintelligibleway.Moreoverwordsarerelativelyeasytolearnandindeedallofusgo【59】learningthemallour【60】.Theyarealsothe【61】stablepartoflanguage.Wordscomeinto【62】changetheirpronunciationsandmeaningsanddisappearcompletelyallwithcomparativeease.Yetitistruethatthe【63】isfocusoflanguage.Itisinwords【64】soundsandmeaningsinterlocktoallowusto【65】withoneanotheranditiswordsthatwearrangetogethertomakesentencesconversationsanddiscourseofallkinds.Thuswehaveaparadoxinthatthemostshort-livedpartoflanguageisalsothecentrewheremeaningpronunciationandgrammarcometogether.
Language Whenmostofusthinkaboutlanguagewethinkfirstaboutwords.Thusthehardestpartoflearningaforeignlanguagemayseemtobememorizing【51】vocabulary;whenweobserveachildfirstacquiringspeechwetalkofhisprogress【52】amatteroflearningnewwords.Wearealso【53】tofeelthattheadultspeakerwiththelargestvocabularyhasthebest【54】ofEnglish.Tothink【55】alanguageasjustastockofwordsis【56】quitewrong.Wordsalonedonot【57】alanguage;agrammaris【58】tocombinetheminsomeintelligibleway.Moreoverwordsarerelativelyeasytolearnandindeedallofusgo【59】learningthemallour【60】.Theyarealsothe【61】stablepartoflanguage.Wordscomeinto【62】changetheirpronunciationsandmeaningsanddisappearcompletelyallwithcomparativeease.Yetitistruethatthe【63】isfocusoflanguage.Itisinwords【64】soundsandmeaningsinterlocktoallowusto【65】withoneanotheranditiswordsthatwearrangetogethertomakesentencesconversationsanddiscourseofallkinds.Thuswehaveaparadoxinthatthemostshort-livedpartoflanguageisalsothecentrewheremeaningpronunciationandgrammarcometogether.
Hetookustoanautomobileshowyesterdayafternoon.
Hisplanshouldsucceedforitseemsquitefeasible.
Language Whenmostofusthinkaboutlanguagewethinkfirstaboutwords.Thusthehardestpartoflearningaforeignlanguagemayseemtobememorizing【51】vocabulary;whenweobserveachildfirstacquiringspeechwetalkofhisprogress【52】amatteroflearningnewwords.Wearealso【53】tofeelthattheadultspeakerwiththelargestvocabularyhasthebest【54】ofEnglish.Tothink【55】alanguageasjustastockofwordsis【56】quitewrong.Wordsalonedonot【57】alanguage;agrammaris【58】tocombinetheminsomeintelligibleway.Moreoverwordsarerelativelyeasytolearnandindeedallofusgo【59】learningthemallour【60】.Theyarealsothe【61】stablepartoflanguage.Wordscomeinto【62】changetheirpronunciationsandmeaningsanddisappearcompletelyallwithcomparativeease.Yetitistruethatthe【63】isfocusoflanguage.Itisinwords【64】soundsandmeaningsinterlocktoallowusto【65】withoneanotheranditiswordsthatwearrangetogethertomakesentencesconversationsanddiscourseofallkinds.Thuswehaveaparadoxinthatthemostshort-livedpartoflanguageisalsothecentrewheremeaningpronunciationandgrammarcometogether.
Aseapenthesizeofafootballfieldawaitsthewhaleina{{U}}isolated{{/U}}bayinWestmanIslands.
Dyslexia Asmanyas20%ofallchildrenintheUnitedStatessufferfromsomeformofthelearningdisorder2calleddyslexia. Expertsondyslexiasaythattheproblemisnotadisease.Theysaythatpersonswithdyslexiauseinformationinadifferentway.Oneoftheworldsgreatthinkersandscientists.AlbertEinsteinwasdyslexic.Einsteinsaidthatheneverthoughtinwordsthewaythatmostpeopledo.Hesaidthathethoughtinpicturesinstead. TheAmericaninventorThomasEdisonwasalsodyslexic.DyslexiafirstwasrecognizedinEuropeandtheUnitedStatesmorethan80yearsago.Manyyearspassedbeforedoctorsdiscoveredthatpersonswiththedisorderwerenotmentallyslowordisabled.Thedoctorsfoundthatthebrainsofpersonswithdyslexiaaredifferent. Inmostpeopletheleftsideofthebrain—thepartthatcontrolslanguageislargerthantherightside.Inpersonswithdyslexiatherightsideofthebrainisbigger.Doctorsarenotsurewhatcausesthisdifference.Howeverresearchhasshownthatdyslexiaismorecommoninmalesthaninfemalesanditisfoundmoreofteninpersonswhoarelefthanded4.Nooneknowsthecauseofdyslexiabutsomescientistsbelievethatitmayresultfromchemicalchangesinababy’’sbodylongbeforeitisborn.Theyaretryingtofindwaystoteachpersonswithdyslexia.Dyslexicpersonsthinkdifferentlyandneedspecialkindsofteachinghelp.Aftertheyhavesolvedtheirproblemswithlanguagetheyoftenshowthemselvestobeespeciallyintelligentorcreative. OneoutoffiveAmericanchildrensuffersfromdyslexia.
Idon'tgetintoa{{U}}panic{{/U}}speakingthelanguagewhenI'minGreeceit'sdrivingontheothersideoftheroadwhichbothersme.
OnAntibodies Substancesforeigntothebodysuchasdisease-causingbacteriaandvirusesandotherinfectiousagentsarerecognizedbythebodysimmunesystemasinvaders.Ournaturaldefensesagainsttheseinfectiousagentsareantibodiesproteinsthatseekouttheantigens抗原andhelpdestroythem. Antibodieshavetwoveryusefulcharacteristics.Firsttheyareextremelyspecific;thatiseachantibodybindstoandattacksoneparticularantigen.Secondsomeantibodiesonceactivatedbytheoccurrenceofadiseasecontinuetoconferresistanceagainstthatdisease.Classicexamplearetheantibodiestothechildhooddiseasesofchickenpox水痘andmeasles. Thesecondcharacteristicofantibodiesmakesitpossibletodevelopvaccines.Avaccine痘苗isapreparationofkilledorweakenedbacteriaorvirusesthatwhenintroducedintothebodystimulatestheproductionofantibodiesagainsttheantigensitcontains. Itisthefirsttraitofantibodiestheirspecificitythatmakesmonoclonalantibodytechnologysovaluable.Notonlycanantibodiesbeusedtherapeutically在治疗上toprotectagainstdisease;theycanalsohelpto.diagnoseawidevarietyofillnessesandcandetectthepresenceofdrugsviralandbacterialproductsandotherunusualorabnormalsubstancesintheblood. Givensuchadiversityofusesforthesediseased-fightingsubstancestheirproductioninpurequantitieshaslongbeenthefocusofscientificinvestigation.Theconventionalmethodwastoinjectalaboratoryanimalwithanantigenandthenafterantibodieshadbeenformedcollectthoseantibodiesfromthebloodserum血清Antibodycontainingbloodserumiscalledantiserum抗血清.Therearetwoproblemswiththismethod:Ityieldsantiserumthatcontainsundesiredsubstancesanditprovidesaverysmallamountofusableantibody. Monoclonalantibodytechnologyallowsustoproducelargeamountsofpureantibodies.inthefollowingway:wecanobtaincellsthatproduceantibodiesnaturally;wealsohaveavailableaclassofcellsthatcangrowcontinuallyincellculture培养.Ifweformahybrid混血儿thatcombinesthecharacteristicofimmortality永生withtheabilitytoproducethedesiredsubstancewewouldhaveineffectafactorytoproduceantibodiesthatworkaroundtheclock. Inmonoclonalantibodytechnologytumorcellsthatcanreplicate重复endlesslyarefusedwithmammaliancellsthatproduceanantibody.Theresultofthiscellfusionisahybridoma杂交瘤whichwillcontinuallyproduceantibodies.Theseantibodiesarecalledmonoclonalbecausetheycomefromonlyonetypeofcellthehybridomacell;antibodiesproducedbyconventionalmethodsontheotherhandarederivedfrompreparationscontainingmanykindsofcellsandhencearecalledpolyclonal.Anexampleofhowmonoclonalantibodiesarederivedisdescribedbelow. Amyelomaisatumorofthebonemarrow骨髓thatcanbeadaptedtogrowpermanendyincellculture.Whenmyelomacellswerefusedwithantibody-producingmammalianspleencellsitwasfoundthattheresultinghybridcellsorhybridomasproducedlargeamountsofmonoclonal骨髓瘤antibody.Thisproductofcellfusioncombinedthedesiredqualitiesofthetwodifferenttypesofcells:theabilitytogrowcontinuallyandtheabilitytoproducelargeamountsofpureantibody. Becauseselectedhybridcellsproduceonlyonespecificantibodytheyaremorepurethanthepolyclonalantibodiesproducedbyconventionaltechniques.Theyarepotentiallymoreeffectivethanconventionaldrugsinfightingdiseasesincedrugsattacknotonlytheforeignsubstancebutthebody’sowncellsaswellsometimesproducingundesirablesideeffectssuchasnausea恶心andallergicreactions.Monoclonalantibodiesattackthetargetmoleculeandonlythetargetmoleculewithnoorgreatlydiminishedsideeffects. Thepolyclonalantibodiesaredifferentfromthemonoclonalonesinallthefollowingwaysexceptthat______.
Language Whenmostofusthinkaboutlanguagewethinkfirstaboutwords.Thusthehardestpartoflearningaforeignlanguagemayseemtobememorizing【51】vocabulary;whenweobserveachildfirstacquiringspeechwetalkofhisprogress【52】amatteroflearningnewwords.Wearealso【53】tofeelthattheadultspeakerwiththelargestvocabularyhasthebest【54】ofEnglish.Tothink【55】alanguageasjustastockofwordsis【56】quitewrong.Wordsalonedonot【57】alanguage;agrammaris【58】tocombinetheminsomeintelligibleway.Moreoverwordsarerelativelyeasytolearnandindeedallofusgo【59】learningthemallour【60】.Theyarealsothe【61】stablepartoflanguage.Wordscomeinto【62】changetheirpronunciationsandmeaningsanddisappearcompletelyallwithcomparativeease.Yetitistruethatthe【63】isfocusoflanguage.Itisinwords【64】soundsandmeaningsinterlocktoallowusto【65】withoneanotheranditiswordsthatwearrangetogethertomakesentencesconversationsanddiscourseofallkinds.Thuswehaveaparadoxinthatthemostshort-livedpartoflanguageisalsothecentrewheremeaningpronunciationandgrammarcometogether.
Thewhalewillbefedifhedoesn't{{U}}hunt{{/U}}forhimself.
AmericansDecrease IncreasinglyhistoriansareblamingdiseasesimportedfromtheOldWorldforthestaggeringdisparity不同betweentheindigenous本土的populationofAmericain1492—newestimatesofwhichsoarashighas100millionorapproximatelyone-sixthofthehumanraceatthattime—andthefewmillionfull-bloodedNativeAmericansaliveattheendofthenineteenthcentury.Thereisnodoubtthatchronicdiseasewasanimportantfactorintheprecipitous险峻的declineanditishighlyprobablethatthegreatestkillerwasepidemicdiseaseespeciallyasmanifestedinvirgin-soil处女地epidemics. Virgin-soilepidemicsarethoseinwhichthepopulationsatriskhavehadnopreviouscontactwiththediseasesthatstrikethemandarethereforeimmunologically免疫学的almostdefenseless.Thatvirgin-soilepidemicswereimportantinAmericanhistoryisstronglyindicatedbyevidencethatanumberofdangerousmaladies病—smallpoxmeasles麻疹malaria疟病yellowfeverandundoubtedlyseveralmore—wereunknowninthepre-ColumbianNewWorld.TheeffectsoftheirsuddenintroductionaredemonstratedintheearlychroniclesofAmericawhichcontainreportsofhorrendous可怕的epidemicsandsteeppopulationdeclinesconfirmedinmanycasesbyrecentequantitativeanalysesofSpanishtributerecordsandothersources.TheevidenceprovidedbythedocumentsofBritishandFrenchcoloniesisnotasdefinitivebecausetheconquerorsofthoseareasdidnotestablishpermanentsettlementsandbegintokeepcontinuousrecordsuntiltheseventiethcenturybywhichtimetheworstepidemicshadprobablyalreadytakenplace.FurthermoretheBritishtendedtodrivethenativepopulationsawayratherthanenslavingthemastheSpaniardsdidsothattheepidemicsofBritishAmericaoccurredbeyondtherangeofcolonistsdirectobservation. EvensothesurvivingrecordsofNorthAmericadocontainreferencestodeadlyepidemicsamongtheindigenouspopulation.In1616—1619anepidemicpossiblyofbubonicorpneumonic肺的plague瘟疫sweptcoastalNewEnglandkillingasmanyasnineoutoften.Duringthe1630’’ssmall-poxthediseasemostfataltotheNativeAmericanpeopleeliminatedhalfthepopulationoftheHuronandIroquoisconfederations.Inthe1820’’sfeverdevastatedthepeopleoftheCoulumbiaRiverareakillingeightoutoftenofthem. UnfortunatelythedocumentationoftheseandotherepidemicsisslightandfrequentlyunreliableanditisnecessarytosupplementwhatlittlewedoknowwithevidencefromrecentepidemicsamongNativeAmericans.Forexamplein1952anoutbreakofmeaslesamongtheNativeAmericaninhabitantsofUngavaBay.Quebecaffected99percentofthepopulationandkilled7percenteventhoughsomehadthebenefitofmodernmedicine.Casessuchasthisdemonstratethatevendiseasesthatarenotnormallyfatalcanhavedevastatingconsequenceswhentheystrikeanimmunologicallydefenselesscommunity. Theprimarypurposeofthepassageisto______.
Shelongedtobeenviedandsoughtafter.
Language Whenmostofusthinkaboutlanguagewethinkfirstaboutwords.Thusthehardestpartoflearningaforeignlanguagemayseemtobememorizing【51】vocabulary;whenweobserveachildfirstacquiringspeechwetalkofhisprogress【52】amatteroflearningnewwords.Wearealso【53】tofeelthattheadultspeakerwiththelargestvocabularyhasthebest【54】ofEnglish.Tothink【55】alanguageasjustastockofwordsis【56】quitewrong.Wordsalonedonot【57】alanguage;agrammaris【58】tocombinetheminsomeintelligibleway.Moreoverwordsarerelativelyeasytolearnandindeedallofusgo【59】learningthemallour【60】.Theyarealsothe【61】stablepartoflanguage.Wordscomeinto【62】changetheirpronunciationsandmeaningsanddisappearcompletelyallwithcomparativeease.Yetitistruethatthe【63】isfocusoflanguage.Itisinwords【64】soundsandmeaningsinterlocktoallowusto【65】withoneanotheranditiswordsthatwearrangetogethertomakesentencesconversationsanddiscourseofallkinds.Thuswehaveaparadoxinthatthemostshort-livedpartoflanguageisalsothecentrewheremeaningpronunciationandgrammarcometogether.
AmericansDecrease IncreasinglyhistoriansareblamingdiseasesimportedfromtheOldWorldforthestaggeringdisparity不同betweentheindigenous本土的populationofAmericain1492—newestimatesofwhichsoarashighas100millionorapproximatelyone-sixthofthehumanraceatthattime—andthefewmillionfull-bloodedNativeAmericansaliveattheendofthenineteenthcentury.Thereisnodoubtthatchronicdiseasewasanimportantfactorintheprecipitous险峻的declineanditishighlyprobablethatthegreatestkillerwasepidemicdiseaseespeciallyasmanifestedinvirgin-soil处女地epidemics. Virgin-soilepidemicsarethoseinwhichthepopulationsatriskhavehadnopreviouscontactwiththediseasesthatstrikethemandarethereforeimmunologically免疫学的almostdefenseless.Thatvirgin-soilepidemicswereimportantinAmericanhistoryisstronglyindicatedbyevidencethatanumberofdangerousmaladies病—smallpoxmeasles麻疹malaria疟病yellowfeverandundoubtedlyseveralmore—wereunknowninthepre-ColumbianNewWorld.TheeffectsoftheirsuddenintroductionaredemonstratedintheearlychroniclesofAmericawhichcontainreportsofhorrendous可怕的epidemicsandsteeppopulationdeclinesconfirmedinmanycasesbyrecentequantitativeanalysesofSpanishtributerecordsandothersources.TheevidenceprovidedbythedocumentsofBritishandFrenchcoloniesisnotasdefinitivebecausetheconquerorsofthoseareasdidnotestablishpermanentsettlementsandbegintokeepcontinuousrecordsuntiltheseventiethcenturybywhichtimetheworstepidemicshadprobablyalreadytakenplace.FurthermoretheBritishtendedtodrivethenativepopulationsawayratherthanenslavingthemastheSpaniardsdidsothattheepidemicsofBritishAmericaoccurredbeyondtherangeofcolonistsdirectobservation. EvensothesurvivingrecordsofNorthAmericadocontainreferencestodeadlyepidemicsamongtheindigenouspopulation.In1616—1619anepidemicpossiblyofbubonicorpneumonic肺的plague瘟疫sweptcoastalNewEnglandkillingasmanyasnineoutoften.Duringthe1630’’ssmall-poxthediseasemostfataltotheNativeAmericanpeopleeliminatedhalfthepopulationoftheHuronandIroquoisconfederations.Inthe1820’’sfeverdevastatedthepeopleoftheCoulumbiaRiverareakillingeightoutoftenofthem. UnfortunatelythedocumentationoftheseandotherepidemicsisslightandfrequentlyunreliableanditisnecessarytosupplementwhatlittlewedoknowwithevidencefromrecentepidemicsamongNativeAmericans.Forexamplein1952anoutbreakofmeaslesamongtheNativeAmericaninhabitantsofUngavaBay.Quebecaffected99percentofthepopulationandkilled7percenteventhoughsomehadthebenefitofmodernmedicine.Casessuchasthisdemonstratethatevendiseasesthatarenotnormallyfatalcanhavedevastatingconsequenceswhentheystrikeanimmunologicallydefenselesscommunity. AccordingtothepassagetheBritishcolonialistsdifferedfromtheSpanishcolonialistsinthattheformer______.
CigarsInstead? Smokingoneortwocigarsadaydoublestheriskofcancersoftheliptonguemouthandthroataccordingtoagovernmentstudy. DailycigarsalsoincreasetheriskoflungcancerandcanceroftheesophagusandincreasetheriskofcancerofthelarynxvoiceboxsixfoldsayresearchersattheNationalCancerInstituteinBethesdaMaryland. Inadditionthereportrevealedthatsmokingthreeorfourcigarsadayincreasedtheriskoforalcancerto8.5timestheriskfornonsmokersandtheriskofesophagealcancerbyfourtimestheriskofnonsmokers. ThehealtheffectsofsmokingcigarsisoneofeightsectionsofthearticleCigars:HealthEffectsandTrends.Theresearchersreportthatcomparedwithacigarettealargecigaremitsupto90timesasmuchcarcinogenictobacco-specificnitrosamines ThisarticleprovidesclearandinvaluableinformationaboutthedisturbingincreaseincigaruseandthesignificantpublichealthconsequencesforthecountrysaidDr.RichardKlausnerdirectoroftheNationalCancerInstituteinastatement. Thedataareclear-theharmfulsubstancesandcarcinogensincigarsmokelikecigarettesareassociatedwiththeincreasedrisksofseveralkindsofcancersaswellasheartandlungdiseasesheadded.Inotherwordscigarsarenotsafealternativestocigarettesandmaybeaddictive. Tothoseindividualswhomaybethinkingaboutsmokingcigarsouradvicesis—don’’t.TothosecurrentlysmokingcigarsquittingistheonlywaytoeliminatecompletelythecancerheartandlungdiseaseriskswarnedKlausner. AccordingtoaNationalCancerInstitutepressreleasetherehaven’’tbeenanystudiesonthehealtheffectsonnonsmokersatcigarsocialeventsbut...asignificantbodyofevidenceclearlydemonstratesanincreasedlungcancerriskfromsecondhandsmoke. Whatisthedoctors’advicetothosecigar-smokers?
Dyslexia Asmanyas20%ofallchildrenintheUnitedStatessufferfromsomeformofthelearningdisorder2calleddyslexia. Expertsondyslexiasaythattheproblemisnotadisease.Theysaythatpersonswithdyslexiauseinformationinadifferentway.Oneoftheworldsgreatthinkersandscientists.AlbertEinsteinwasdyslexic.Einsteinsaidthatheneverthoughtinwordsthewaythatmostpeopledo.Hesaidthathethoughtinpicturesinstead. TheAmericaninventorThomasEdisonwasalsodyslexic.DyslexiafirstwasrecognizedinEuropeandtheUnitedStatesmorethan80yearsago.Manyyearspassedbeforedoctorsdiscoveredthatpersonswiththedisorderwerenotmentallyslowordisabled.Thedoctorsfoundthatthebrainsofpersonswithdyslexiaaredifferent. Inmostpeopletheleftsideofthebrain—thepartthatcontrolslanguageislargerthantherightside.Inpersonswithdyslexiatherightsideofthebrainisbigger.Doctorsarenotsurewhatcausesthisdifference.Howeverresearchhasshownthatdyslexiaismorecommoninmalesthaninfemalesanditisfoundmoreofteninpersonswhoarelefthanded4.Nooneknowsthecauseofdyslexiabutsomescientistsbelievethatitmayresultfromchemicalchangesinababy’’sbodylongbeforeitisborn.Theyaretryingtofindwaystoteachpersonswithdyslexia.Dyslexicpersonsthinkdifferentlyandneedspecialkindsofteachinghelp.Aftertheyhavesolvedtheirproblemswithlanguagetheyoftenshowthemselvestobeespeciallyintelligentorcreative. Generallyspeakingdyslexiaismorecommoninleft-handedmalesthaninright-handedfemales.
Language Whenmostofusthinkaboutlanguagewethinkfirstaboutwords.Thusthehardestpartoflearningaforeignlanguagemayseemtobememorizing【51】vocabulary;whenweobserveachildfirstacquiringspeechwetalkofhisprogress【52】amatteroflearningnewwords.Wearealso【53】tofeelthattheadultspeakerwiththelargestvocabularyhasthebest【54】ofEnglish.Tothink【55】alanguageasjustastockofwordsis【56】quitewrong.Wordsalonedonot【57】alanguage;agrammaris【58】tocombinetheminsomeintelligibleway.Moreoverwordsarerelativelyeasytolearnandindeedallofusgo【59】learningthemallour【60】.Theyarealsothe【61】stablepartoflanguage.Wordscomeinto【62】changetheirpronunciationsandmeaningsanddisappearcompletelyallwithcomparativeease.Yetitistruethatthe【63】isfocusoflanguage.Itisinwords【64】soundsandmeaningsinterlocktoallowusto【65】withoneanotheranditiswordsthatwearrangetogethertomakesentencesconversationsanddiscourseofallkinds.Thuswehaveaparadoxinthatthemostshort-livedpartoflanguageisalsothecentrewheremeaningpronunciationandgrammarcometogether.
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