TPO阅读44文本答案翻译.docx

TPO阅读44文本答案翻译.docx

《TPO阅读44文本答案翻译.docx》由会员分享，可在线阅读，更多相关《TPO阅读44文本答案翻译.docx（25页珍藏版）》请在冰豆网上搜索。

TPO阅读44文本答案翻译

TPO-44

FromFishtoTerrestrialVertebrates

OneofthemostsignificantevolutionaryeventsthatoccurredonEarthwasthe

transitionofwater-dwellingfishtoterrestrialtetrapods（four-limbedorganisms

withbackbones）.Fishprobablyoriginatedintheoceans,andourfirstrecordsofthemareinmarinerocks.However,bytheDevonianPeriod（408millionto362millionyearsago）,theyhadradiatedintoalmostallavailableaquatichabitats,including

freshwatersettings.Oneofthegroupswhosefossilsareespeciallycommoninrocks

depositedinfreshwateristhelobe-finnedfish.

ThefreshwaterDevonianlobe-finnedfishrhipidistiancrossopterygianisofparticularinteresttobiologistsstudyingtetrapodevolution.Thesefishlivedinriverchannelsandlakesonlargedeltas.Thedeltarocksinwhichthesefossilsarefoundarecommonlyredduetooxidizedironminerals,indicatingthatthedeltas

formedinaclimatethathadalternatewetanddryperiods.Iftherewereperiodsofdrought,anyadaptationsallowingthefishtosurvivethedryconditionswouldhavebeenadvantageous.Intheserhipidistians,severalsuchadaptationsexisted.

Itisknownthattheyhadlungsaswellasgillsforbreathing.Crosssectionscutthroughsomeofthefossilsrevealthatthemudfillingtheinteriorofthecarcass

differedinconsistencyandtexturedependingonitslocationinsidethefish.These

differencessuggestasadlikecavitybelowthefrontendofthegutthatcanonlybeinterpretedasalung.Gillswereundoubtedlythemainsourceofoxygenforthese

fish,butthelungsservedasanauxiliarybreathingdeviceforgulpingairwhenthewaterbecameoxygendepleted,suchasduringextendedperiodsofdrought.So,thesefishhadalreadyevolvedoneoftheprimerequisitesforlivingonland:

theabilitytouseairasasourceofoxygen.

Asecondadaptationofthesefishwasinthestructureofthelobefins.Thefinswerethick,fleshy,andquitesturdy,withamedianaxisofbonedownthecenter.Theycouldhavebeenusedasfeeblelocomotordevicesonland,perhapsgoodenough

toallowafishtoflopitswayfromonepoolofwaterthatwasalmostdrytoanadjacentpondthathadenoughwaterandoxygenforsurvival.Thesefinseventuallychangedintoshort,stubbylegs.ThebonesofthefinsofaDevonianrhipidistianexactlymatchinnumberandpositionthelimbbonesoftheearliestknowntetrapods,theamphibians.Itshouldbeemphasizedthattheevolutionoflungsandlimbswasinnosenseananticipationoffuturelifeonland.Theseadaptationsdevelopedbecausetheyhelpedfishtosurviveintheirexistingaquaticenvironment.

WhatecologicalpressuresmighthavecausedfishestograduallyabandontheirwateryhabitatandbecomeincreasinglyIand-dwellingcreatures?

Changesinclimate

duringtheDevonianmayhavehadsomethingtodowiththisiffreshwaterareasbecameprogressivelymorerestricted.Anotherimpetusmayhavebeennewsourcesoffood.

Theedgesofpondsandstreamssurelyhadscattereddeadfishandotherwater-dwellingcreatures.・naddition,plantshademergedintoterrestrial

habitatsinareasnearstreamsandponds,andcrabsandotherarthropodswerealso

membersofthisearliestterrestrialcommunity.BThus,bytheDevoniantheland

habitatmarginaltofreshwaterwasprobablyarichsourceofproteinthatcouldbe

exploitedbyananimalthatcouldeasilyclimboutofwater.■Evideneefromteeth

suggeststhattheseearliesttetrapodsdidnotutilizelandplantsasfood;theywerepresumablycarnivorousandhadnotdevelopedtheabilitytofeedonplants.

■

Howdidthefirsttetrapodsmakethetransitiontoaterrestrialhabitat?

Likeearlylandplantssuchasrhyniophytes,theymadeonlyapartialtransition;theywerestillquitetiedtowater.However,manyproblemsthatfacedearlylandplantswerenotapplicabletothefirsttetrapods.Theancestorsoftheseanimalsalready

hadacirculationsystem,andtheyweremobile,sothattheycouldmovetowatertodrink.Furthermore,theyalreadyhadlungs,whichrhipidistianspresumablyusedforauxiliarybreathing.Theprincipalchangesfortheearliesttetrapodswereintheskeletalsystem—changesinthebonesofthefins,thevertebralcolumn,pelvic

girdle,andpectoralgirdle.

P1:

OneofthemostsignificantevolutionaryeventsthatoccurredonEarthwasthe

transitionofwater-dwellingfishtoterrestrialtetrapods（four-limbedorganisms

withbackbones）.Fishprobablyoriginatedintheoceans,andourfirstrecordsofthemareinmarinerocks.However,bytheDevonianPeriod（408millionto362millionyearsago）,theyhadradiatedintoalmostallavailableaquatichabitats,includingfreshwatersettings.Oneofthegroupswhosefossilsareespeciallycommoninrocks

depositedinfreshwateristhelobe-finnedfish.

1.Paragraph1supportswhichofthefollowingstatementsaboutfishevolution?

A.Lobe-finnedfishwereamongtheearliesttypesoffishtoappear.

B.Fishbeganlivinginfreshwaterhabitatsonlyafteroriginatingelsewhere.

C.Lobe-finnedfishradiatedintoalmostallavailableaquatichabitats.

D.DuringtheDevonian,Iobe-finnedfishweremorecommoninmarinethaninfreshwaterhabitats.

P2：

ThefreshwaterDevonianlobe-finnedfishrhipidistiancrossopterygianisofparticularinteresttobiologistsstudyingtetrapodevolution.Thesefishlivedin

riverchannelsandlakesonlargedeltas.Thedeltarocksinwhichthesefossilsarefoundarecommonlyredduetooxidizedironminerals,indicatingthatthedeltas

formedinaclimatethathadalternatewetanddryperiods.Iftherewereperiodsofdrought,anyadaptationsallowingthefishtosurvivethedryconditionswouldhavebeenadvantageous.Intheserhipidistians,severalsuchadaptationsexisted.

Itisknownthattheyhadlungsaswellasgillsforbreathing.Crosssectionscutthroughsomeofthefossilsrevealthatthemudfillingtheinteriorofthecarcassdifferedinconsistencyandtexturedependingonitslocationinsidethefish.Thesedifferencessuggestasadlikecavitybelowthefrontendofthegutthatcanonly

beinterpretedasalung.Gillswereundoubtedlythemainsourceofoxygenforthesefish,butthelungsservedasanauxiliarybreathingdeviceforgulpingairwhenthewaterbecameoxygendepleted,suchasduringextendedperiodsofdrought.So,thesefishhadalreadyevolvedoneoftheprimerequisitesforlivingonland:

theabilitytouseairasasourceofoxygen.

2.Accordingtoparagraph2,whatdothemineralsinthedeltarockscontainingrhipidistiancrossopterygianfossilsreveal?

A.Thesedeltasformedindryperiodsbutgraduallybecamewetter.

B.Thesedeltascontaindifferenttypesofironmineralsthandothesurroundingareas.

C.Mostrhipidistiancrossopterygianfishdiedwhentheclimatebecamedry.

D.Rhipidistiancrossopterygianfishlivedinareasthatexperieneedalternatedryandwetperiods.

3.Theword"advantageous"inthepassageisclosestinmeaningto

A.beneficial

B.necessary

C.remarkable

D.common

4.Inparagraph2,whydoestheauthorincludetheinformationthatmudinside

rhipidistiancrossopterygianfossilsdifferedinconsistencyandtexturedepending

onwherethemudwaslocated?

A.Toprovideevidencethatrhipidistiancrossopterygianlivedinriverchannelsandlakesonlargedeltas.

B.Toidentifyaneffectoftheoxidationofironmineralsontheevolutionofrhipidistiancrossopterygian.

C.Tohelpexplainwhyscientistshaveconcludedthatrhipidistiancrossopterygianprobablyhadlungs.

D.Toexplainwhyscientistsdecidedtocutcrosssectionsthroughsomefossilsof

rhipidistiancrossopterygian.

5.Whichofthesentencesbelowbestexpressestheessentialinformationinthehighlightedsentenceinthepassage?

Incorrectchoiceschangethemeaninginimportantwaysorleaveoutessentialinformation.

A.Becausethelungsofthesefishwereabletoprovideonlyasmallamountofoxygen,thesefishobtainedmostoftheiroxygenthroughtheirgillsduringperiodsof

drought.

B.Duringperiodsofextendeddrought,thesefishusedtheirlungstoincreasetheirintakeofoxygenbeyondthelevelsabsorbedbythegillsinnormaltimes.

C.Althoughthesefishprimarilyusedtheirgillstoobtainoxygen,theyusedtheirlungstoobtainoxygenfromtheairwhentherewasnotenoughinthewater.

D.Duringperiodsofextendeddrought,thegillsbecameanauxiliarybreathingdevice

andthelungsbecamethemainsourceofoxygenforthesefish.

6.Whichofthesentencesbelowbestexpressestheessentialinformationinthehighlightedsentenceinthepassage?

Incorrectchoiceschangethemeaninginimportantwaysorleaveoutessentialinformation.

A.Becausethelungsofthesefishwereabletoprovideonlyasmallamountofoxygen,thesefishobtainedmostoftheiroxygenthroughtheirgillsduringperiodsof

drought.

B.Duringperiodsofextendeddrought,thesefishusedtheirlungstoincreasetheirintakeofoxygenbeyondthelevelsabsorbedbythegillsinnormaltimes.

C.Althoughthesefishprimarilyusedtheirgillstoobtainoxygen,theyusedtheirlungstoobtainoxygenfromtheairwhentherewasnotenoughinthewater.

D.Duringperiodsofextendeddrought,thegillsbecameanauxiliarybreathingdevice

andthelungsbecamethemainsourceofoxygenforthesefish.

P3：

Asecondadaptationofthesefishwasinthestructureofthelobefins.Thefinswerethick,fleshy,andquitesturdy,withamedianaxisofbonedownthecenter.Theycouldhavebeenusedasfeeblelocomotordevicesonland,perhapsgoodenough

toallowafishtoflopitswayfromonepoolofwate