考研《英语》模考试题及答案卷三.docx

考研《英语》模考试题及答案卷三.docx

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考研《英语》模考试题及答案卷三

2021年考研《英语》模考试题及答案（卷三）

　Lookingbeyondthe10-yearperiod，thebotanistsestimatethatsome3，000nativeplantspeciesmaybecomeextinctintheforeseeablefuture—morethan10percentoftheapproximately25，000speciesofplantsintheUnitedStates.

　　Thesituationisthesameorworseinmostotherpartsoftheworld.Itisestimatedthatabout20percentofEarth‘sapproximately300，000plantspeciesareindanger.Mostoftheseplantsareinthetropicalrainforeststhatarebeingcutdown，andmanyhavenotevenbeenidentifiedyet.

　　WhyisextinctionthreateningsomanyU.S.species?

Themainreasonisthedestructionofhabitats.Thisdestructioniscaused，especiallyintheEasternUnitedStates，bylanddevelopment，suchastheconstructionofshoppingcentersandhousingtracts.IntheWesternstates，thepoormanagementofpubliclandshasbeenacriticalfactor.There，manyhabitatshavebeendestroyedbythespreadofexoticplantspecies.1）Forexample，Junegrass，whichwasintroducedfromEuropeinthelate1800s，hasinvadedhundredsofsquarekilometersofWesternlands，pushingoutsomenativespeciesofgrassthatarelessabletocompetefortheusuallyscarcemoisture.

　　Publicindifferencehasalsocontributedtotheproblem.2）AmericanshaveralliedtothecauseofendangeredanimalssuchaswhoopingcranesandAfricanelephants，buttheyseemunconcernedaboutendangeredplants.Perhapstheyconsiderwildanimalstobepublicproperty，butplantsarethepropertyoftheownerofthelandonwhichtheygrow.

　　Theconsequencesofhabitatdestructionareoftenmostseriousinthetropicsandsubtropics.Thoseregionshaveamuchgreaternumberofplantspeciesthanarefoundincoolerclimates.Andmanyspeciesgrowinonlyasmallarea，increasingtheprobabilityoftheirbeingwipedout.Itisnotsurprising，therefore，thatnearly75percentofthe680speciesonthemost-endangeredlistarelocatedinjustthreestatesandPuertoRico.Hawaiihas21percent;Texas，12.2percent;Florida，10.6percent;andPuertoRico，10.1percent.Butnearlyallofthe50stateshaveatleastafewnativeplantsthatareamongthosefacingextinction.

　　Savingendangeredplantsisimportantforseveralreasons.Amongthoseplants，theremaybesomethatproducesubstancesthatcouldbeofvalueinmakingmedicines.Othersmightpossessgenetictraitsthatcouldbeusedtoimprovecropplants.Wemightalsofindthatsomeplantsareworthgrowingfortheirownsake—asfoodorperhapsfortheoilintheirseeds.Butbeyondsuchpracticalapplications，thereisasenseoflosswhenanyspecies—aplantasmuchasananimal—disappearsfromthefaceoftheEarthforever.

　　1.Inanotherdecade，itisestimatedthat____.

　　[A]morethan10percentofthenativeplantsintheUnitedStatesmaydieout

　　[B]approximately25，000speciesofplantsintheUnitedStateswillbeextinct

　　[C]20percentofEarth‘sapproximately300，000plantspecieswillbeextinct

　　[D]20percentofEarth‘sapproximately300，000plantspeciesmaybecomeextinct

　　2.WhichofthefollowingisNOTmentionedasacauseofplantspeciesextinction?

　　[A]Carelessintroductionofforeignplantspecies.

　　[B]Over-developmentof1andforcommercialuse.

　　[C]Publicignoranceofthepresentsituation.

　　[D]Inappropriategovernmentallandprotectionpolicies.

　　3.Inwhatwayarethepublicindifferenttothepresentsituation?

　　[A]Theyarestillunawareofthecauseoflanddestruction.

　　[B]Theypaytoomuchattentiontoendangeredanimals.

　　[C]Theydonotgivedueattentiontosavingendangeredplants.

　　[D]Theyareselfishenoughtoprotectonlytheirownproperties.

　　4.Plantspeciesinthetropicsandsubtropicsaremostvulnerableinthat____.

　　[A]agreaternumberofplantspeciesarefoundtherethanincoolerregions

　　[B]manyplantspeciesgrowinonlyasmallareaintheseregions

　　[C]theseregionsfrequentlybecomethefirsttargetsofdeforestation

　　[D]countrieswithintheseregionshaveaworsesenseofenvironmentalprotection

　　5.AllofthefollowingarepracticalconsiderationsforprotectingplantspeciesEXCEPT____.

　　[A]medicinaluseofplantspecies

　　[B]utilizingtheirgenetictraitstodevelopbetterplantspecies

　　[C]asenseoflossthatsomespeciesdisappearevenbeforetheyareidentified

　　[D]productionoffoodandoilforthedinnertableoutofthem

　　1.[A]参阅第一段，这句话的意思是：

在展望10年后的情况时植物学家们预计，在不久的将来，3000种植物——占美国近25000种植物的10%以上——将可能灭绝。

[D]不对，第二段第二句只提到了这些植物受到了（灭绝的）威胁，而不是将会灭绝。

　　2.[D]第三段第四句虽然提到了公地管理不善是造成植物生长地遭破坏的根本原因，但是，这里并未提到是政策本身不好，还是政策执行得不好。

有关[A]参阅第三段第五、六句，第五句中exotic意为“外（国）来的”。

有关[B]参阅第四段第二句。

有关[C]参阅第四段：

该段批评美国人对保护动物非常热心，但对濒临灭绝的植物似乎漠不关心。

在作者看来，其中的原因是他们认为野生动物是公共财产，而植物是土地所有者的私有财产。

　　3.[C]参阅第2题题解。

　　4.[B]参阅第五段第三句。

　　5.[C]意为：

当意识到有些物种甚至还没来得及被鉴别出就消失了时而产生的一种失落感。

参阅最后一段最后一句，请注意本句中的beyondsuchpracticalapplications.有关[A]参阅最后一段第二句;有关[B]参阅最后一段第三句，这句的意思指借鉴其他植物的基因特性并利用基因工程的方法来改进作物。

有关[D]参阅最后一段第四句。

　　Tropicalrainforestscoveroveranareaofnearly3billionacres，orabout8.3percentoftheEarth‘stotal1andsurface.Theseremarkableforestsaresharedbysome50countriesonfivecontinents.Biologistsbelievethatrainforestsarethehomeofperhapshalftheworld’sbioticspecies，aboutfive-sixthsofwhichhavenotyetbeendescribedandnamed.

　　Throughoutmostofhistory，rainforestswereconsideredtoberemote，inaccessible，andunpleasantplaces，andasaresulttheywere1ittleaffectedbyhumanactivities.Inthepresentcentury，however，rainforestshavebeenexploitedandruinedataquickeningpace，andinthelastdecadeorso，tropicaldeforestationhasbecomeoneoftheEarth‘smostseriousenvironmentalproblems.Therateofdeforestationisspectacular—51acresperminute;74，000acresperday;27millionacresperyear.MorethanhalfoftheoriginalAfricanrainforestisnowgone;about45percentofAsia’srainforestnolongerexists;theproportioninLatinAmericaisapproaching40percent.

　　Astheforestgoes，sogoesitsanimallife.Inthemid-1980sitwascalculatedthattropicaldeforestationwasresponsiblefortheextinctionofonespeciesperday;by1990itwasestimatedthattheratewasonespeciesperhour.

　　Moreover，lossoftheforestscontributestoincreasedsoilerosion，drought，flooding，worseningwaterquality，decliningagriculturalproductivity，andgreaterpovertyforruralinhabitants.Inaddition，atmosphericcarbondioxidecontinuestobeincreasedbecausetherearefewertreestoabsorbitandbecauseburningoftreesforforestclearingreleasesmoretotheair.

　　Theironyoftropicaldeforestationisthattheanticipatedeconomicbenefitsareusuallyillusory.Muchoftheforestclearing，especiallyinLatinAmerica，isinresponsetothesocialpressureofovercrowdingandpovertyinsocietieswheremostofthepeoplearelandless.Thegovernmentsopenup“newlands”forsettlementintherainforest.Thesettlersclearthelandforcropgrowingorlivestockraising.Theresultalmostalwaysisaninitialoneortwoyearsofhighsoilproductivity，followedbypooryearsasfertilitydeclinesandthesoilbeginstosufferfromerosion.

　　Theforests，ofcourse，arerenewable.Ifleftalonebyhumans，theycanregenerate，aslongasthereareseedtreesintheneighborhoodandthesoilhasnotlostallitsnutrients.Thelossofbioticdiversity，however，ismuchmoreserious.Extinctionisanirrecoverableprocess.Valuablepotentialresourcesmaydisappearbeforetheyareevendiscovered.Naturalgenotypesthatcouldbecombinedwithagriculturalcropsoranimalstoresistdisease，insects，parasites，andotherenvironmentalstressesmayalsobelost.Last，butnotleast，isthepossibilitythatmanysmall，isolatedvaluablegroupsofnativepeoplemaybewipedout.

　　Muchconcernhasbeenexpressedabouttropicaldeforestation，andsomeconcretestepshavebeentaken.Thedevelopmentofagroforestry（plantingcropswithtrees，ratherthancuttingdownthetreesandreplacingthemwithcrops）isbeingfosteredinmanyareas.InBrazil，whichhasbyfarthelargestexpanseofrainforest，some46，000squaremilesofreserveshavebeensetaside，andBrazilianlawrequiresthatanydevelopmentintheAmazonregionleavehalfofthelandinitsnaturalstate.In1985acomprehensiveworldplan，sponsoredbytheWorldBank，theWorldResourcesInstitute，andtheUnitedNationsDevelopmentProgramme，wasintroduced.Itproposesconcrete，country-by-countrystrategiestocombattropicaldeforestation.Itisan$8billion，five-yearproject，dealingwitheverythingconcerningtheprotectionofrainforests.

　　Meanwhile，thesoundsoftheaxeandthechain-sawandthebulldozercontinuetobeheardthroughoutthetropicalforestlands.

　　1.Inthepast，rainforestswerenearlyleftintactbecause____.

　　[A]peoplethenhadabettersenseofenvironmentalprotection

　　[B]peoplethenknewbetterhowtoprotectthem

　　[C]peoplethenlookedatrainforestsinsomeawe

　　[D]peoplethendidnotknowhowtoexploitthem

　　2.WhichofthefollowingisNOTmentionedasaresultofdeforestation?

　　[A]Lossofspeciesdiversity.

　　[B]Increasedpovertyfortheconcernedcountries.

　　[C]Increasedatmosphericpollution.

　　[D]Lossofculturediversity.

　　3.Itcanbeinferredfromthepassagethatforestdestructionmainlyresultsfrom____.

　　[A]people‘sdesiretomeettheireconomicneeds

　　[B]people‘signoranceoftheimportanceofforeststobioticspecies

　　[C]people‘sneedtoburnfueltowarmtheirhouses

　　[D]people‘sdesiretoopenupmorefarmland

　　4.People‘sattempttocleartheforesttoopenupnewlandsoftenhastheresultof____.

　　[A]leavingevenmorepeoplehomeless

　　[B]expandingsettlementbutdestroyingtheland

　　[C]findingmorelandforlandlesspeopletocultivate

　　[D]renewingtheforestataslowerpace

　　5.Thetoneoftheauthor‘sconclusionseemstobe____.

　　[A]optimistic[B]