Thelightchangedsuddenly.Thefirstraysofsunlightstretched（延伸）acrossthesea.Thesunwaspushingitswayovertheedgeoftheworld.
　　Overthefirstrocks,alongtothepoint.Timglancedback.Thebeachwasstillempty.Thesunsailedhigherinthesky.
　　Hecouldseethecavenow,evendarkerinthemorninglight.Thesandturnedsilverthendarkgoldasthewaterflowedawayfromit.Hehadtoforcehimselftogocloser.Whywasitsomuchmoremysterious（神秘的）now?Butitwouldbesillytogobacknowaftersomuchtrouble.Heneedn'tgoinalltheway…
　　43.WhatdidTimdoatthebeginningofthestory?
　　A.Heleftthehousequietly.B.Hehadbreakfastathome.
　　C.Heleftanoteonthefreezer.D.Heputasweaterinhisschoolbag.
　　44."Hesettledforsomebiscuits"（inParagraph3）meansthatTim.
　　A.hadtoleavethebiscuitsonthetable
　　B.likedbiscuitsbetterthansandwiches
　　C.hadtotakebiscuitsinsteadofsandwiches
　　D.couldonlyfindsomebiscuitsinthekitchen
　　45.WhatmadeitpossibleforTimtoseetheentrytothecave?
　　A.Theheightofthefirstrocks.
　　B.Theupsanddownsofthewaves.
　　C.Thechangeinthepositionofthesun.
　　D.Thevaststretchofthesunlitbeach.
　　46.WhichofthefollowingstatementsisTRUEaccordingtothestory?
　　A.Thesealookedlikeapieceofgold.
　　B.SeabirdsflewawaywhenTimarrived.
　　C.Timwastheonlypersononthebeach.
　　D.TheskygotdarkasTimreachedthecave.
　　47.Inthestory,Tim'smood（心情）changedfrom.
　　A.lonelinesstocrazinessB.anxiousnesstoexcitement
　　C.helplessnesstohappinessD.eagernesstonervousness

　　D
　　ThesceneintheHollywoodmovieTheDayAfterTomorrow,whereglobalwarmingcouldsoonturntheglobalclimate（气候）intoanewiceage,mayneveroccur,accordingtonewresearch.
　　Thenexticeagecouldbe15,000yearsaway,sayEuropeanscientistswholastmonthannouncedacontinuousrecordof740,000yearsofclimatedate（数据）obtainedfromtheAntarcticice.
　　Scientistsfrom10nationshavenowalmostcompletelydrilledthrougha3,000-meterdepthoficehighintheAntarcticmainland.Theyfigureoutthattheareawheresummertemperaturescanfallto,hasatleast900,000yearsofsnowfalls,keptasneatlyasthegrowthringsofatree.Andtheiceandaircaughtineachlayer（层）havebeguntoanswerquestionsabouttheclimatesinthepast.
　　Theresultsshowthattherehavebeeneighticeagesinthepast740,000yearsandeightwarmerperiods.Andbycomparingthepatternofglobalconditionstodaywiththoseofthepast,theresearchersreportedinNaturethatthepresentwarmperiodcouldlastanother15,000years.
　　Researchsuggeststhatthereisaverycloseconnectionbetweengreenhousegaslevelsandglobalaveragetemperatures.Italsoshowsthatcarbondioxide（二氧化碳）levelsarethehighestforatleast440,000years.
　　"Ifpeoplesaytoyou:thegreenhouseeffectisagoodthingbecausewewouldgointoaniceageotherwise,ourdatesayno,anewiceageisnothangingoverourheads,"saidEricWolfffromtheBritishAntarcticSurvey."Nowwehaveeightexamplesofhowtheclimategoesinandoutoficeages…andyoucanlearnwhattherulesarethatgointotheclimatemodelsthattellusaboutthefuture."
　　Scientistsfoundthatwhenevertemperaturesroseinthefrozenrecord,sodidcarbondioxidelevel."In440,000yearswehaveneverseengreenhousegasgetasthickasitistoday,"saidDrWolff.
　　48.IndrillingthroughtheiceinAntarctica,scientistshavefoundthat.
　　A.thelowesttemperaturethereis
　　B.thedepthoficeis3,000meters
　　C.theicehasexistedfor15,000years
　　D.snowfallsarekeptincertainpatterns
　　49.Theinformationoftheglobalclimateconditionsinthepastcanbeobtained
　　through.
　　A.separatingcarbondioxidefromtheair
　　B.examiningthegrowthringsoftrees
　　C.comparingtemperaturesindifferentareas
　　D.studyingtheiceandaircaughtineachlayer
　　50.WecaninferfromEricWolff'swordsthat.
　　A.thereissomethingwrongwiththedata
　　B.greenhouseeffectisalwaysabadthing
　　C.anewiceagewillnotcomeinthenearfuture
　　D.greenhousegaswillgetthickinthefuture
　　51.Whatwouldbethebesttitleforthepassage?
　　A.ResearchovertheAntarcticarea.
　　B.Warmperiodtolastabout15,000years.
　　C.Reportontheeighticeagesinthepast.
　　D.Hollywoodmoviesandtheglobalclimate.

　　E
　　Noonecanfailtostandinawed（令人敬畏的）admirationofthegreatdiscoveriesofhistory-Newton'slawsofmotion,Kepler'sprinciplesofplanetarymovement,Einstein'sgeneraltheoryofrelativity.Equallyawe-inspiringareartisticcreationsinpainting,theatre,music,andliterature,whichhavealsobeenbroughtaboutbydiscoverythroughpersonalefforts.Whatdotheseextraordinaryachievementsofwell-knownscientistsandartistshavetodowithproblemsolving?
　　Agreatscientificdiscoveryoragreatworkofartissurelytheresultofproblem-solvingactivity.Thesolutiontoaproblem,wearetold,oftencomestothinkersina"flashofinsight（顿悟）",althoughtheymayhavebeenturningtheproblemoverintheirmindsforsometime.Asaparticularformofproblemsolving,thesecreativeactsarebasedonthebroadknowledgegainedinthepast,whetherthisbeofthe"public"sortknowntoscience,orofthe"private"sortknowntotheartist.