大学英语六级考试试点考试样卷试题册.docx
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大学英语六级考试试点考试样卷试题册
大学英语六级考试试点考试样卷(试题册)
窗体顶端
大学英语六级考试试点考试样卷(试题册)
PartⅠWriting(30minutes)
Directions:
Forthispart,youareallowed30minutestowriteashortessayentitledSayNotoPiratedProducts.Youshouldwriteatleast150wordsfollowingtheoutlinegivenbelow:
1.目前盗版的现象比较严重
2.造成这种现象的原因及其危害
3.我们应该怎么做
Usefulwordsandexpressions:
盗版:
piracy(n.)
盗版产品:
piratedproducts
知识产权:
intellectualpropertyrights
侵犯版权:
infringesb’scopyright;copyrightinfringement
SayNotoPiratedProducts
PartⅡReadingComprehension(SkimmingandScanning)(15minutes)
Directions:
Inthispart,youwillhave15minutestogooverthepassagequicklyandanswerthequestionsonAnswerSheet1.
Forquestions14,mark
Y(forYES)ifthestatementagreeswiththeinformationgiveninthepassage;
N(forNO)ifthestatementcontradictstheinformationgiveninthepassage;
NG(forNOTGIVEN) iftheinformationisnotgiveninthepassage.
Forquestions510,completethesentenceswiththeinformationgiveninthepassage.
Rainforests
Tropicalrainforestsarethemostdiverseecosystem(生态系统)onEarth,andalsotheoldest.Today,tropicalrainforestscoveronly6percentoftheEarth’sgroundsurface,buttheyarehometooverhalfoftheplanet’splantandanimalspecies.
WhatIsaRainforest?
Generallyspeaking,arainforestisanenvironmentthatreceiveshighrainfallandisdominatedbytalltrees.Awiderangeofecosystemsfallintothiscategory,ofcourse.Butmostofthetimewhenpeopletalkaboutrainforests,theymeanthetropicalrainforestslocatedneartheequator.
Theseforestsreceivebetween160and400inchesofrainperyear.Thetotalannualrainfallisspreadprettyevenlythroughouttheyear,andthetemperaturerarelydipsbelow60degreesFahrenheit.
Thissteadyclimateisduetothepositionofrainforestsontheglobe.BecauseoftheorientationoftheEarth’saxis,theNorthernandSouthernhemisphereseachspendpartoftheyeartiltedawayfromthesun.Sincerainforestsareatthemiddleoftheglobe,locatedneartheequator,theyarenotespeciallyaffectedbythischange.Theyreceivenearlythesameamountofsunlight,andthereforeheat,allyear.Consequently,theweatherintheseregionsremainsfairlyconstant.
Theconsistently wet,warmweatherandamplesunlightgiveplantlifeeverythingitneedstothrive.Treeshavetheresourcestogrowtotremendousheights.andtheyliveforhundreds,eventhousands,ofyears.Thesegiants,whichreach60to150ftintheair,formthebasicstructureoftherainforest.Theirtopbranchesspreadwideinordertocapturemaximumsunlight.Thiscreatesathickcanopy(树冠)levelatthetopoftheforest,withthinnergreenerylevelsunderneath.Somelargetreesgrowsotallthattheyeventoweroverthecanopylayer.
Asyougolower,downintotherainforest,youfindlessandlessgreenery.Theforestfloorismadeupofmoss,fungi,anddecayingplantmatterthathasfallenfromtheupperlayers.Thereasonforthisdecreaseingreeneryisverysimple:
Theoverabundanceofplantsgatheringsunlightatthetopoftheforestblocksmostsunlightfromreachingthebottomoftheforest,makingitdifficultforrobustplantstothrive.
TheForestfortheTrees
Theamplesunlightandextremelywetclimateofmanytropicalareasencouragethegrowthoftoweringtreeswithwidecanopies.Thisthicktoplayeroftherainforestdictatesthelivesofallotherplantsintheforest.Newtreeseedlingsrarelysurvivetomakeittothetopunlesssomeoldertreesdie,creatinga“hole”inthecanopy.Whenthishappens,alloftheseedlingsonthegroundlevelcompeteintenselytoreachthesunlight.
Manyplantspeciesreachthetopoftheforestbyclimbingthetalltrees.Itismucheasiertoascendthisway,becausetheplantdoesn’thavetoformitsownsupportingstructure.
Someplantspecies,calledepiphytes,growdirectlyonthesurfaceofthegianttrees.Theseplants,whichincludeavarietyoforchidsandferns,makeupmuchoftheunderstory,thelayeroftherainforestrightbelowthecanopy.Epiphytesarecloseenoughtothetoptoreceiveadequatelight,andtherunofffromthecanopylayerprovidesallthewaterandnutrients(养分)theyneed,whichisimportantsincetheydon’thaveaccesstothenutrientsintheground.
StranglersandButtresses
Someepiphyteseventuallydevelopintostranglers.Theygrowlong,thickrootsthatextenddownthetreetrunkintotheground.Astheycontinuetogrow,therootsformasortofwebstructureallaroundthetree.Atthesametime,thestranglerplant’sbranchesextendupward,spreadingoutintothecanopy.Eventually,thestranglermayblocksomuchlightfromabove,andabsorbsuchahighpercentageofnutrientsfromthegroundbelow,thatthehosttreedies.
Competitionovernutrientsisalmostasintenseascompetitionforlight.Theexcessiverainfallrapidlydissolvesnutrientsinthesoil,makingitrelativelyinfertileexceptatthetoplayers.Forthisreason,rainforesttreerootsgrowoutwardtocoverawiderarea,ratherthandownwardtolowerlevels.Thismakesrainforesttreessomewhatunstable,sincetheydon’thaveverystronganchorsintheground.Sometreescompensateforthisbygrowingnaturalbuttresses.Thesebuttressesarebasicallytreetrunksthatextendoutfromthesideofthetreeanddowntotheground,givingthetreeadditionalsupport.
Rainforesttreesaredependentonbacteriathatarecontinuallyproducingnutrientsintheground.Rainforestbacteriaandtreeshaveaveryclose,symbiotic(共生的)relationship.Thetreesprovidethebacteriawithfood,intheformoffallenleavesandothermaterial,andthebacteriabreakthismaterialdownintothenutrientsthatthetreesneedtosurvive.
Oneofthemostremarkablethingsaboutrainforestplantlifeisitsdiversity.ThetemperaterainforestsofthePacificNorthwestaremainlycomposedofadozenorsotreespecies.Atropicalrainforest,ontheotherhand,mighthave300distincttreespecies.
AllCreatures,GreatandSmall
Rainforestsarehometothemajorityofanimalspeciesintheworld.Andagreatnumberofspecieswhonowliveinotherenvironments,includinghumans,originallyinhabitedtherainforests.Researchersestimatethatinalargerainforestarea,theremaybemorethan10milliondifferentanimalspecies.
Mostofthesespecieshaveadaptedforlifeintheupperlevelsoftherainforest,wherefoodismostplentiful.Insects,whichcaneasilyclimborflyfromtreetotree,makeupthelargestgroup(antsarethemostabundantanimalintherainforest).Insectspecieshaveahighlysymbioticrelationshipwiththeplantlifeinarainforest.Theinsectsmovefromplanttoplant,enjoyingthewealthoffoodprovidedthere.Astheytravel,theinsectsmaypickuptheplants’seeds,droppingthemsomedistanceaway.Thishelpstodispersethepopulationoftheplantspeciesoveralargerarea.
Thenumerousbirdsoftherainforestalsoplayamajorpartinseeddispersal.Whentheyeatfruitfromaplant,theseedspassthroughtheirdigestivesystem.Bythetimetheyexcrete(排泄)theseeds,thebirdsmayhaveflownmanymilesawayfromthefruit-bearingtree.
Therearealsoalargenumberofreptilesandmammalsintherainforest.Sincetheweatherissohotandhumidduringtheday,mostrainforestmammalsareactiveonlyatnight,duskordawn.Themanyrainforestbatspeciesareespeciallywelladaptedforthislifestyle.Usingtheirsonar,batsnavigateeasilythroughthemassoftreesintherainforest,feedingoninsectsandfruit.
Whilemostrainforestspeciesspendtheirlivesinthetrees,thereisalsoalotoflifeontheforestfloor.Greatapes,wildpigs,bigcatsandevenelephantscanallbefoundinrainforests.Thereareanumberofpeoplewholiveintherainforests,aswell.Thesetribes—which,upuntilrecently,numberedinthethousands—arebeingforcedoutoftherainforestsatanalarmingratebecauseofdeforestation.
Deforestation
Inthepasthundredyears,humanshavebegundestroyingrainforestsatanalarmingrate.Today,roughly1.5acresofrainforestaredestroyedeverysecond.Peoplearecuttingdowntherainforestsinpursuitofthreemajorresources:
Landforcrops
Lumberforpaperandotherwoodproducts
Landforlivestockpastures
Inthecurrenteconomy,peopleobviouslyhaveaneedforalloftheseresources.Butalmostallexpertsagreethat,overtime,wewillsuffermuchmorefromthedestructionoftherainforeststhanwewillbenefit.
Theworld’srainforestsareanextremelyvaluablenaturalresource,tobesure,butnotfortheirlumberortheirland.TheyarethemaincradleoflifeonEarth,andtheyholdmillionsofuniquelifeformsthatwehaveyettodiscover.Destroyingtherainforestsiscomparabletodestroyinganunknownplanet—wehavenoideawhatwe’relosing.Ifdeforestationcontinuesatitscurrentrate,theworld’stropicalrainforestswillbewipedoutwithin40years.
1.VirtuallyallplantandanimalspeciesonEarthcanbefoundintropicalrainforests.
2.Thereisnotmuchchangeintheweatherinthetropicalrainforestsalltheyearround.
3.ThelargestnumberofrainforestsintheworldarelocatedontheAfricancontinent.
4.Belowthecanopylevelofatropicalrainforestgrowsanoverabundanceofplants.
5.Newtreeseedlingswillnotsurvivetoreachthecanopylevelunless .
6.Epiphytes,whichformmuchoftheunderstoryoftherainforest,getalltheirwat