劍橋商務(wù)英語(yǔ)考試高級(jí)閱讀輔導(dǎo)材料

BOBDOUGHTY:TounderstandwhyLaBreaisanimportantscientificresearchcenterwemusttravelbackthroughtimealmostfortythousandyears.Pictureanareathatisalmostdesertland.Thesunishot.Apig-likecreaturesearchesforfood.Itusesitsshort,flatnosetodignearasmalltree.Itfindsnothing.Thepigstartstowalkaway,butitcannotmoveitsfeet.

Theyarecoveredwithathick,blacksubstance.Themoreitstrugglesagainsttheblacksubstance,thedeeperitsinks.Itnowscreamsinfearandfightswildlytogetloose.

Lessthanakilometeraway,ahugecat-likecreaturewithtwolongfrontteethhearsthescreams.It,too,ishungry.Travelingacrossthegroundatgreatspeed,thecatnearstheareawherethepigisfightingforitslife.

Thecatjumpsonthepigandkillsit.Thepigdiesquickly,andthecatbeginstoeat.Whenitattemptstoleave,thecatfindsitcannotmove.Themorethebigcatstruggles,thedeeperitsinksintotheblacksubstance.

Beforemorning,thecatisdead.Itsbody,andthebonesofthepig,slowlysinkintothestickyblackhole.

FAITHLAPIDUS:Scientistssaythestorywehavetoldyouhappenedagainandagainoveraperiodofmanythousandsofyears.TheblacksubstancethattrappedtheanimalscameoutoftheEarthasoil.

Theoildried,leavingbehindapartlysolidsubstancecalledasphalt.Intheheatofthesun,theasphaltsoftened.Whatevertoucheditwouldoftenbecometrappedforever.

Inseventeensixty-nine,agroupofSpanishexplorersvisitedthearea.TheywereledbyGaspardePortola,governorofLowerCalifornia.

ThegroupstoppedtoexaminethestickyblacksubstancethatcoveredtheEarth.Theycalledthearea“LaBrea,”theSpanishwordsfor“thetar.”

Manyyearslater,settlersusedthetar,orasphalt,onthetopsoftheirhousestokeepwaterout.Theyfoundanimalbonesintheasphalt,butthrewthemaway.Innineteen-oh-six,scientistsbegantostudythebonesfoundinLaBrea.Tenyearslater,theowneroftheland,GeorgeAllanHancock,gaveittothegovernmentofLosAngeles.Hisgiftcarriedonecondition.HesaidLaBreacouldonlybeusedforscientificwork.

BOBDOUGHTY:Today,theLaBreaTarPitsareknowntoscientistsaroundtheworld.Theareaisconsideredoneoftherichestareasoffossilbonesintheworld.Itisanextremelyvaluableplacetostudyancientanimals.ScientistshaverecoveredmorethanonemillionfossilbonesfromtheLaBreaTarPits.Theyhaveidentifiedmorethansixhundreddifferentkindsofanimalsandplants.

Thefossilsarefromcreaturesassmallasinsectstothosethatwerebiggerthanamodernelephant.Thesecreaturesbecametrappedaslongagoasfortythousandyears.Itisstillhappeningtoday.SmallbirdsandanimalsstillbecometrappedintheLaBreaTarPits.

AP

Theskeletonofasaber-toothcatatthePageMuseumThemuseumalsohasmanyfossilremainsofthehugecatsthatoncelivedinthearea.Theyarecalledsaber-toothedcatsbecauseoftheirlong,fierceteeth.Scientistshavefoundmorethantwothousandexamplesofthehugecats.

Themuseumalsohasthousandsoffossilremainsofanancientkindofwolf.Scientistsbelievelargegroupsofwolvesbecamestuckwhentheycametofeedonanimalsalreadytrappedintheasphalt.

BOBDOUGHTY:Innineteensixty-nine,scientistsbegandiggingatoneareaofLaBreacalledPitNinety-One.TheyhavefoundmorethanfortythousandfossilsinPitNinety-One.Morethanninety-fivepercentofthemammalbonesarefromjustsevendifferentanimals.Threewereplant-eaters.Theywerethewesternhorse,theancientbisonandatwo-metertallanimalcalledtheHarlan’sgroundsloth.

Fouroftheanimalsweremeat-eatinghunters.Thesewerethesaber-toothcat,theNorthAmericanlion,thedirewolfandthecoyote.Alltheseanimals,exceptthedog-likecoyote,havedisappearedfromtheEarth.

FAITHLAPIDUS:Researcherssayninetypercentofthefossilsfoundarethoseofmeat-eatinganimals.Theysaythisisasurprisebecausetherehavealwaysbeenmoreplant-eatersintheworld.Theresearcherssayeachplant-eaterthatbecametrappedcausedmanymeat-eaterstocometotheplacetofeed.They,too,becametrapped.

RanchoLaBreahasalsobeenatrapformanydifferentkindsofinsects.Scientistsfreethesedeadinsectsbywashingtheasphaltawaywithspecialchemicals.TheLaBreainsectsgivescientistsacloselookatthehistoryofinsectsinsouthernCalifornia.

TheLaBreaTarPitshavealsoprovidedsciencewithinterestinginformationabouttheplantsthatgrewinthearea.Formanythousandsofyears,plantseedslandedinthestickyasphalt.Theseedshavebeensavedforresearch.Scientistsalsohavefoundpollenfrommanydifferentkindsofplants.

Theseedsandpollen,orthelackofthem,canshowsevereweatherchangesoverthousandsofyears.Scientistssaytheseprovideinformationthathashelpedthemunderstandthehistoryoftheenvironment.Theseedsandpollenhaveleftaforty-thousand-yearrecordoftheenvironmentandweatherforthisareaofCalifornia.

BOBDOUGHTY:DiggingatPitNinety-OnewasrecentlysuspendedinordertopayclosertoattentiontoanewdiscoverycalledProjectTwenty-Three.Intwothousandsixanearbyartmuseumbegananundergroundbuildingproject.

LaBreascientistshadachancetoinvestigateanareathatotherwisewouldhavebeenimpossibletostudy.Thisareaturnedouttobeveryrichinfossils.So,twenty-threehugecontainersoftar,clayandmudwereremovedfromtheareaforresearch.ThisiswhytheprojectisnowknownasProjectTwenty-Three.

Scientistshavefullyexaminedonlyseveralboxesofearthandtar.Itwilltakeyearstocompleteallofthecontainers.Butscientistshavesofarcountedoversevenhundredpartsfromdifferentorganisms.Onehugediscoverywasthenearlycompleteskeletonofamalemammoth.ResearchershavenamedthemammothZed.Thisisthelargestmammotheverfoundinthearea.

RanchoLaBreascientistspublishanInternetblogthatdocumentsthisexcitingproject.Itdescribesindetailthehugeamountofworkinvolvedincarefullyexaminingthemanylayersoftarandearth.Forexample,youcanlearnaboutthedegreasingmachine.Researchersplaceabigblockoftarintothemachine.Itremovestheoilymaterial,leavingbehindhundredsoffossils.

FAITHLAPIDUS:Eachyear,thousandsofvisitorscometoseethefossilsatRanchoLaBrea.TheyvisittheGeorgeC.PageMuseum.MisterPagewasawealthymanwhobecameveryinterestedinthescientificworkbeingdoneatthetarpits.Hegavethemoney