國(guó)家實(shí)行有利于節(jié)能和環(huán)境保護(hù)的產(chǎn)業(yè)政策,(),發(fā)展節(jié)能環(huán)保型產(chǎn)業(yè)。
A、鼓勵(lì)發(fā)展重化工業(yè)D
暫無(wú)解析
Don'twashthosefossils!
StandardmuseumpracticecanwashawayDNA.
1.Washing,brushingandvarnishingfossils—allstandardconservationtreatmentsusedbymanyfossilhuntersandmuseumcuratorsalike—vastlyreducesthechancesofrecoveringancientDNA.
2.Instead,excavatorsshouldbehandlingatleastsomeoftheirbountywithgloves,andfreezingsamplesastheyarefound,dirtandall,concludesapaperintheProceedingsoftheNationalAcademyofSciencestoday.
3.AlthoughmanypalaeontologistsknowanecdotallythatthisisthebestwaytouptheoddsofextractinggoodDNA,Eva-MariaGeigloftheJacquesMonodInstituteinParis,France,andhercolleagueshavenowshownjusthowimportantconservationpracticescanbe.Thisinformation,theysay,needstobehammeredhomeamongthepeoplewhoareactuallyoutinthefielddiggingupbones.
4.Geiglandhercolleagueslookedat3,200-year-oldfossilbonesbelongingtoasingleindividualofanextinctcattlespecies,calledanaurochs.ThefossilsweredugupatasiteinFranceattwodifferenttimes—eitherin1947,andstoredinamuseumcollection,orin2004,andconservedinsterileconditionsat-20oC.
5.Theteam'sattemptstoextractDNAfromthe1947bonesallfailed.Thenewlyexcavatedfossils,however,allyieldedDNA.
6.Becausetheboneshadbeenburiedforthesameamountoftime,andinthesameconditions,theconservationmethodhadtobetoblamesaysGeigl."AsmuchDNAwasdegradedinthese57yearsasinthe3,200yearsbefore,"shesays.
Washin,washout
7.Becausemanypalaeontologistsbasetheirworkontheshapeoffossilsalone,theirmethodsofconservationarenotdesignedtopreserveDNA,Geiglexplains.
8.Thebiggestproblemishowtheyarecleaned.Fossilsareoftenwashedtogetheron-siteinalargebath,whichcanallowwater—andcontaminantsintheformofcontemporaryDNA—topermeateintotheporousbones."NotonlyistheauthenticDNAgettingwashedout,butcontaminationisgettingwashedin,"saysGeigl.
9.MostancientDNAspecialistsknowthisalready,saysHendrikPoinar,anevolutionarygeneticistatMcMasterUniversityinOntario,Canada.Butthatdoesn'tmeanthatbestpracticehasbecomewidespreadamongthosewhoactuallyfindthefossils.
10.GettingholdoffossilsthathavebeenpreservedwiththeirDNAinmindreliesoncloserelationshipsbetweenlab-basedgeneticistsandtheexcavators,sayspalaeogeneticistSvantePbooftheMaxPlanckInstituteforEvolutionaryAnthropologyinLeipzig,Germany.Andthatonlyoccursinexceptionalcases,hesays.
11.Pbo'steam,whichhasbeensequencingNeanderthalDNA,continuallyfacestheseproblems."WhenyouwanttostudyancienthumanandNeanderthalremains,there'sabigissueofcontaminationwithcontemporaryhumanDNA,"hesays.
12.Thisdoesn'tmeanthatallmuseumspecimensarefatallyflawed,notesPbo.TheNeanderthalfossilsthatwererecentlysequencedinhisownlab,forexample,hadbeenpartofamuseumcollectiontreatedinthetraditionalway.ButPboiskeentoseesamplesoffossilsfromeverymajorfindpreservedinlinewithGeigl'srecommendations—justincase.
Warmandwet
13.Geiglherselfbelievesthat,withcooperationbetweenbenchandfieldresearchers,preservingfossilsproperlycouldopenupavenuesofdiscoverythathavelongbeenassumedclosed.
14.Muchhumanculturaldevelopmenttookplaceintemperateregions.DNAdoesnotsurvivewellinwarmenvironmentsinthefirstplace,andcanvanishwhenfossilsarewashedandtreated.Forthisreason,Geiglsays,mostancientDNAstudieshavebeendoneonpermafrostsamples,suchasthewoollymammoth,oronremainsshelteredfromtheelementsincoldcaves—includingcavebearandNeanderthalfossils.
15.Betterconservationmethods,andafocusonfreshfossils,couldboostDNAextractionfrommoredelicatespecimens,saysGeigl.Andthatcouldshedmorelightonthestoryofhumanevolution.
(640wordsnature)
Glossary
Palaeontologists古生物學(xué)家
Aurochs歐洲野牛
Neanderthal(人類學(xué))尼安德特人,舊石器時(shí)代的古人類。
Permafrost(地理)永凍層
Questions1-6
AnswerthefollowingquestionsbyusingNOMORETHANTHREEWORDSforeachanswer.
1.Howdidpeopletraditionallytreatfossils?
2.WhatsuggestionsdoGeiglandhercolleaguesgiveonwhatshouldbedonewhenfossilsarefound?
3.Whatproblemsmaybeposediffossilbonesarewashedon-site?NameONE.
4.WhatcharacteristicdofossilboneshavetomakethemsusceptibletobecontaminatedwithcontemporaryDNAwhentheyarewashed?
5.Whatcouldbebetterunderstoodwhenconservationtreatmentsareimproved?
6.Thepassagementionedseveralanimalspeciesstudiedbyresearchers.Howmanyofthemarementioned?
Questions7-11
Dothefollowingstatementsagreewiththeinformationgiveninthepassage?PleasewriteTRUEifthestatementagreeswiththewriterFALSEifthestatementdoesnotagreewiththewriterNOTGIVENifthereisnoinformationaboutthisinthepassage.
7.IntheirpaperpublishedintheProceedingsoftheNationalAcademyofSciences,GeiglandhercolleagueshaveshownwhatconservationpracticesshouldbefollowedtopreserveancientDNA.
8.ThefossilbonesthatGeiglandhercolleaguesstudiedareallfromthesameaurochs.
9.Geneticistsdon'thavetoworkonsite.
10.OnlynewlyexcavatedfossilbonesusingnewconservationmethodssuggestedbyGeiglandhercolleaguescontainancientDNA.
11.Paaboisstillworriedaboutthepotentialproblemscausedbytreatmentsoffossilsintraditionalway.
Questions12-13
CompletethefollowingthestatementsbychoosingletterA-Dforeachanswer.
12.“Thisinformation”inparagraph3indicates:
[A]ItiscriticaltofollowproperpracticesinpreservingancientDNA.
[B]ThebestwayofgettinggoodDNAistohandlefossilswithgloves.
[C]Fossilhuntersshouldwearhome-madehammerswhilediggingupbones.
[D]Manypalaeontologistsknowhowoneshoulddointreatingfossils.
13.ThestudyconductedbyGeiglandhercolleaguessuggests:
[A]thefactthatancientDNAcannotberecoveredfromfossilbonesexcavatedinthepast.
[B]thecorrelationbetweentheamountofburyingtimeandthatoftherecoveredDNA.
[C]thepaceatwhichDNAdegrades.
[D]thecorrelationbetweenconservationpracticesanddegradationofDNA.
Thespeakersuggestsostrichfarmsareprofitablebecause____
Investingthousandsofpoundsintherecruitmentandtrainingofeachnewgraduaterecruitmaybejustthebeginning.Choosingthewrongcandidatemayleaveanorganisationpayingforyearstocome.
Fewcompanieswillhaveescapedallofthefollowingfailures:peoplewhopanicatthefirstsightofstress;thosewithlongimpressivequalificationswhoseemincapableoflearning;hypochondriacswhoseabsenteerecordbecomesastonishing;andtheunstablepersonlaterdiscoveredtobeathieforworse.
Lessdramatic,butjustasmuchaproblem,isthepersonwhosimplydoesnotcomeuptoexpectations,whodoesnotquitedeliver;whoneverbecomesahigh-flierorevenasteadyperformer;theemployeewithafinefuturebehindthem.
Thefirstpointtobearinmindattherecruitmentstageisthatpeopledon’tchange.Intelligencelevelsdeclinemodestly,butchangelittleovertheirworkinglife.Thesameistrueofabilities,suchaslearninglanguagesandhandlingnumbers.
Mostpeopleliketothinkthatpersonalitycanchange,particularlythemorenegativefeaturessuchasanxiety,lowesteem,impulsivenessoralackofemotionalwarmth.Butdatacollectedover50yearsgivesaclearmessage:stillstableafteralltheseyears.Extrovertsbecomeslightlylessextroverted;theacutelyshyappearalittlelessso,butthefundamentalsremainmuchthesame.Personalcrisescanaffectthewaywecopewiththings:wemighttakeupordropdrink,drugs,religionorrelaxationtechniques,whichcanbehaveprettydramaticeffects.Skillscanbeimproved,andnewonesintroduced,butatratherdifferentrates.Peoplecanbegroomedforajob.Justaspoliticiansarecarefullyrepackagedthroughdress,hairstyleandspeechspecialists,sopeoplecanbesentontrainingcourses,diplomasorexperimentalweekends.Butthereisacosttoallthiswhichmaybemorethanthepriceofthecourse.Bettertoselectforwhatyouactuallyseeratherthanattempttochangeit.
()1.Thepurposeofthispassageistogivemanagerstheadvicethat.
A.Employersshouldselectcandidatesfortheirpotential.
B.Employersshouldselectcandidatesforwhattheyareratherthanfortheirpotential.
C.Employersshouldselectthenewlygraduatedandsendthemontrainingcourses,diplomasorexperimentalweekends.
D.Employersshouldselectexperiencedcandidatestoavoidspendingthousandsofpoundsintraining.
()2.Accordingtothepassage,whichofthefollowingstatementsistrue?.
A.Absolutely,Peopledon’tchangeduringtheirworkinglives.
B.Generally,peoplechangetoalargeextentduringtheirworkinglives.
C.Fundamentally,peoplestaythesameduringtheirworkinglives.
D.Normally,peopledon’tchangeatallduringtheirworkinglives.
()3.Whatdoesafinefuturebehindthem(line3ofparagraph3)means?.
A.Somepeoplewillcertainlyhaveapromisingfuturethoughtheyarenotverycompetentintheirpresentwork.
B.Somepeopledon’thaveanypotentialfortheirworkthoughtheyareemployed.
C.Somepeoplecanhaveabrightfuturethoughtheycan’tdotheirworkwell.
D.Somepeoplehavepotentialwhentheyareemployed,butneverrealizethatpotential.
()4.Accordingtothepassage,people’sbasicabilitieslikelanguagelearningandnumeracy.
A.changelittleovertheirworkinglife.
B.neverchangeovertheirworkinglife.
C.changefundamentallyovertheirworkinglife.
D.changeprofoundlyovertheirworkinglife.
()5.Theworddeliver(line2ofparagraph3)means.
A.totakegoodstotheplacesorpeopletheyareaddressedto
B.togiveaspeech
C.todowhatyoupromisedtodo
D.tohelpawomantogivebirthtoababy.
Bodylanguagealsocalled:
Thesefiguresaregrossunderestimatesofthetrueincidenceofoccupationalill-health.