notes目题指代强化众妙之门私家笔记

例子题的中心句有没有可能在后面？——（1）段落内部的逻辑结构（2）段落在文章中的意义——段落间的关联6找不到第6期精读团的文 了15616Paragraph6:Thusaproportionofthetotalvolumeofanysediment,looseorcemented,consistsofemptyspace.Mostcrystallinerocksaremuchmoresolid;acommonexceptionisbasalt,aformofsolidifiedvolcaniclava,whichissometimesfulloftinybubblesthatmakeitveryporous.Paragraph7:Theproportionofemptyspaceinarockisknownasitsporosity.Butnotethatporosityisnotthesameaspermeability,whichmeasurestheeasewithwhichwatercanflowthroughamaterial;thisdependsonthesizesoftheindividualcavitiesandthecreviceslinkingthem.11.Whatisthemainpurposeofparagraph○Toexinwhywatercanflowthrough○Toemphasizethelargeamountofemptyspaceinall○Topointoutthatarockcannotbebothporousand○Todistinguishbetweentworelatedpropertiesof转折意味：porVSperParagraph6:Butneitherthehumanimitativeinstinctnorapenchantforfantasybyitselfleadstoanautonomoustheater.Therefore,additionalexnationsareneeded.Onenecessaryconditionseemstobeasomewhatdetachedviewofhumanproblems.Forexample,onesignofthisconditionistheappearanceofthecomicvision,sincecomedyrequiressufficientdetaenttoviewsomedeviationsfromsocialnormsasridiculousratherthanasseriousthreatstothewelfareoftheentiregroup.Anotherconditionthatcontributestothedevelopmentofautonomoustheateristheemergenceoftheaestheticsense.Forexample,someearlysocietiesceasedtoconsidercertainritesessentialtotheirwell-beingandabandonedthem,nevertheless,theyretainedaspartsoftheiroraltraditionthemythsthathadgrownuparoundtheritesandadmiredthemfortheiricqualitiesratherthanfortheirreligioususefulness.11.Whydoestheauthormention○Togiveanexampleofearlytypesof○Toexinhowtheaterhelpsasocietyrespondtothreatstoits○Tohelpexinwhy entisneededforthedevelopmentof○Toshowhowtheatricalperformers edetachedfromothermembersof【Cdevelopmentoftheaterleadsto...theaterParagraph4：Thereisstillnouniversallyagreed-onexnationforwhythereshouldbesuchadramaticcessationoftreegrowthattheuppertimberline.Variousenvironmentalfactorsmayyarole.Toomuchsnow,forexample,cansmothertrees,andavalanchesandsnowcreepcandamageordestroythem.Late-lyingsnowreducestheeffectivegrowingseasontothepointwhereseedlingscannotestablishthemselves.Windvelocityalsoincreaseswithaltitudeandmaycauseseriousstressfortrees,asismadeevidentbythedeformedshapesathighaltitudes.Somescientistshaveproposedthatthepresenceofincreasinglevelsofultravioletlightwithelevationmayyarole,whilebrowsingandgrazinganimalsliketheibexmaybeanothercontributingfactor.Probablythemostimportantenvironmentalfactoristemperature,forifthegrowingseasonistooshortandtemperaturesaretoolow,treeshootsandbudscannotmaturesufficientlytosurvivethewintermonths.Inparagraph4,whatistheauthor’smainpurposeinthediscussionofthedramaticcessationoftreegrowthattheuppertimberline?○Toarguethatnoneofseveralenvironmentfactorsthatarebelievedtocontributetothatphenomenondoinfactyaroleincausingit.○Toargueinsupportofoneparticularexnationofthatphenomenonagainstseveralcompetingexnations○Toexinwhytheprimaryenvironmentalfactorresponsibleforthatphenomenonhasnotyetbeenidentified○TopresentseveralenvironmentalfactorsthatmaycontributetoasatisfactoryexnationofthatphenomenonParagraph6:Muchoftheworld’sgreatarchitecturehasbeenconstructedofstonebecauseofitsbeauty,permanence,andavailability.Inthepast,wholecitiesgrewfromthearduoustaskofcuttingandpilingstoneupon.Someoftheworld’sfineststonearchitecturecanbeseenintheruinsoftheancientIncacityofMachuPicchuhighintheeasternAndesMountainsofPeru.Thedoorwaysandwindowsaremadepossiblebycingovertheopenspacesthickstonebeamsthatsupporttheweightfromabove.Astructuralinventionhadtobemadebeforethephysicallimitationsofstonecouldbe eandnewarchitecturalformscouldbecreated.Thatinventionwasthearch,acurvedstructureoriginallymadeofseparatestoneorbricksegments.ThearchwasusedbytheearlyculturesoftheMediterraneanareachieflyforundergrounddrains,butitwastheRomanswhofirstdevelopedandusedthearchextensivelyinabovegroundstructures.Romanbuildersperfectedthesemicirculararchmadeofseparateblocksofstone.Asamethodofspanningspace,thearchcansupportgreaterweightthanahorizontalbeam.Itworksincompressiontodiverttheweightaboveitouttothesides,wheretheweightisbornebytheverticalelementsoneithersideofthearch.Thearchisamongthemanyimportantstructuralbreakthroughsthathavecharacterizedarchitecturethroughoutthecenturies.Whydoestheauthorincludeadescriptionofhowthe“doorwaysandwindows”ofMachuPicchuwereconstructed?○ToindicatethatthecombinedskeletonsandskinsofthestonebuildingsofMachuPicchuweresimilartoigloosandadobestructures○ToindicatethedifferentkindsofstonesthathadtobecuttobuildMachu○Toprovideanillustrationofthekindofconstructionthatwasrequiredbeforearcheswereinvented○ToexinhowancientbuildersreducedtheamountoftimenecessarytoconstructbuildingsfromstoneTS==Paragraph3:ThefirstwellsweredrilledintotheOgallaladuringthedroughtyearsoftheearly1930s.Theensuingrapidexpansionofirrigationagriculture,especiallyfromthe1950sonward,transformedtheeconomyoftheregion.Morethan100,000wellsnowtaptheOgallala.Modernirrigationdevices,eachcapableofspraying4.5millionlitersofwateraday,haveproducedalandscapedominatedbygeometricpatternsofcirculargreenislandsofcrops.OgallalawaterhasenabledtheHighinsregiontosupplysignificantamountsofthecotton,sorghum,wheat,andcorngrownintheUnitedStates.Inaddition,40percentofAmericangrain-fedbeefcattlearefattenedhere.5.Inparagraph3,whydoestheauthorprovidetheinformationthat40percentofAmericancattlearefattenedintheHigh ○TosuggestthatcropcultivationisnotthemostimportantpartoftheeconomyoftheHighins○ToindicatethatnotalleconomicactivityintheHighinsisdependenton○ToprovideanotherexampleofhowwaterfromtheOgallalahastransformedtheeconomyoftheHighins○Tocontrastcattle-fatteningpracticesintheHighinswiththoseusedinotherregionoftheUnitedStates 、.5神马的都是例子，快速掠过；最后一句也是例子，而且是inaddition并列。Paragraph5:Eventhekindofstabilitydefinedassimplelackofchangeisnotalwaysassociatedwithumdiversity.Atleastintemperatezones,umdiversityisoftenfoundinmid-successionalstages,notintheclimaxcommunity.Oncearedwoodmatures,forexample,thekindsofspeciesandthenumberofindividualsgrowingonthefloorarereduced.Ingeneral,diversity,byitself,doesnotensurestability.Mathematicalmodelsofecosystemslikewisesuggestthatdiversitydoesnotguaranteeecosystemstability—justtheopposite,infact.Amorecomplicatedsystemis,ingeneral,morelikelythanasimplesystemtobreakdown.Afifteen-speedracingbicycleismorelikelytobreakdownthanachild’stricycle.9.Inparagraph5,whydoestheauthorprovidetheinformationthat“Afifteen-speedracingbicycleismorelikelytobreakdownthanachild’s○Toillustrateageneralprincipleaboutthestabilityofsystemsbyusinganeverydayexample○Todemonstratethatanunderstandingofstabilityinecosystemscanbeappliedtohelpunderstandstabilityinothersituations○Tomakeacomparisonthatsupportstheclaimthat,ingeneral,stabilityincreaseswithdiversity○Toprovideanexamplethatcontradictsmathematicalmodelsof(因为前面还有题目)现在我们假设已经做前面的题目，于是读到了Amoreforexamplebreakdown，一模一样的。证实了这个就是用例子来证明前面的“越复杂越容breakdown”。stabilitybreakdown越稳定越不容易Paragraph2:Oneofthemostpuzzlingaspectsofthepaintingsistheirlocation.Otherrockpaintings—forexample,thoseofBushmeninSouthAfrica—areeitherlocatednearcaveentrancesorcompleyintheopen.CavepaintingsinFranceandSpain,however,areinrecessesandcavernsfarremovedfromoriginalcaveentrances.Thismeansthatsweredtoworkincrampedspacesandwithoutsourcesofnaturallight.Italsoimpliesthatwhoevermadethemdidnotwantthemtobeeasilyfound.Sincecavedwellersnormallylivedclosetoentrances,theremusthavebeensomereasonwhysomanygenerationsofLascauxcavedwellershidtheirart.4.WhydoestheauthormentionBushmeninSouthAfricainparagraph○Tosuggestthatancient sfromallovertheworldpaintedanimalson○Tocontrastthelocationoftheirrockpaintingstothosefoundat○Tosupporttheclaimthat sworkedincramped○Togiveanexampleofotherswhopaintedinhidden看完第一句找到中心词aspects 个forexample，好，头脑简单一点，读选项：AlocationBCD24hiddenlocationBhowever，转折意味：BSnearVSF&SParagraph3:Scholarsofferthreerelatedbutdifferentopinionsaboutthemysteriousoriginandsignificanceofthesepaintings.Oneopinionisthatthepaintingswerearecordofseasonalmigrationsmadebyherds.Becausesomepaintingsweremadedirectlyoverothers,oblitingthem,itisprobablethatapainting’svalueendedwiththemigrationitpictured.Unfortunay,thisexnationfailstoexinthehiddenlocations,unlessthemigrationswerecelebratedwithsecretceremonies.Whydoestheauthormentionsecret○Topresentacommonopinionheldbymany○Tosuggestasimilaritybetweentwoopinionsheldby○Tosuggestapossibleexnationforaweaknessinanopinionexpressedinthepassage○Togiveevidencethatcontradictsamajoropinionexpressedinthe出现一个指代thisexnation，指代的是？前两句话的Oneopinion——seasonalmigrationsABCParagraphAthirdopiniontakespsychologicalmotivationmuchfurtherintotherealmoftribalceremoniesandmystery:thebeliefthatcertainanimalsassumedmythicalsignificanceasancientancestorsorprotectorsofagiventribeorclan.Twotypesofimagessubstantiatethistheory:thestrange,indecipherablegeometricshapesthatappearnearsomeanimals,andthefewdrawingsofmen.Wherevermenappeartheyarecrudelydrawnandtheirbodiesareelongatedandrigid.Somemenareinapronepositionandsomehavebirdoranimalheads.Advocatesforthisopinionpointtoreportsfrompeoplewho consciousnessbetweenwakingandslee.Uniformly,thesepeopleexperiencedweightlessnessandthesensationthattheirbodieswerebeingstretchedlengthwise.Advocatesalsopointtopeoplewhobelievethatthesofnatureareinhabitedbyspirits,particularlyshamans*whobelievethatananimal’sspiritandenergyistransferredtothemwhileinatrance.OneLascauxnarrativepicture,whichshowsamanwithabirdlikeheadandawoundedanimal,wouldseemtolendcredencetothisthirdopinion,butthereisstillmuchthatremainsunexined.Forexample,whereistheproofthatmaninthepictureisashaman?Hecouldaseasilybeahunterwearingaheadmask.Manytribalhunters,includingsomeNativeAmericans,camouflagedthemselvesbywearinganimalheadsandhides.substantiate9.Accordingtoparagraph5,whydosomescholarsrefertoatrancestatetohelpunderstandthecavepaintings?○Toexinthestateofconsciousnesstheswereinwhentheypaintedtheirpictures○Todemonstratethemythicalsignificanceofthestrangegeometric○Toindicatethattrancestateswereoftenassociatedwithactivitiesthattookceinsidecaves○Togiveapossiblereasonforthestrangeappearanceofthemenpaintedonthecavewallstwotypestwotypes:thestrange,andfewdrawingsofTW呢？当然，仔细读下来，B指代错误，然而做题时恐没空这么仔细），所以了B】】Paragraph5:Largewindfarmsmightalsointerferewiththeflightpatternsofmigratorybirdsincertainareas,andtheyhavekilledlargebirdsofprey(especiallyhawks,falcons,andeagles)thatprefertohuntalongthesameridgelinesthatareidealforwindturbines.Thekillingofbirdsofpreybywindturbineshaspittedenvironmentalistswhochampionwildlifeprotectionagainstenvironmentalistswhopromoterenewablewindenergy.Researchersareevaluatinghowseriousthisproblemisandhopetofindwaystoeliminateorsharplyreducethisproblem.Someystsalsocontendthatthenumberbirdskilledbywindturbinesisdwarfedbybirdskilledbyotherhuman-relatedsourcesandbythepotentiallossofentirebirdspeciesfrompossibleglobalwarming.RecordeddeathsofbirdsofpreyandotherbirdsinwindfarmsintheUnitedStatescurrentlyamounttonomorethan300peryear.Bycontrast,intheUnitedStatesanestimated97millionbirdsarekilledeachyearwhentheycollidewithbuildingsmadeofteglass,57millionarekilledonhighwayseachyear;atleast3.8milliondieannuallyfrompollutionandpoisoning;andmillionsofbirdsareelectrocutedeachyearbytransmissionanddistributionlinescarryingpowerproducedbynuclearandcoalpowernts.9.Inparagraph5,whydoestheauthorgivedetailsabouttheestimatednumbersofbirdskilledeachyear?○Toarguethatwindfarmsshouldnotbebuiltalongridge○Topointoutthatthedeathsofmigratorybirdsexceedthedeathsofbirdsof○Toexinwhysomeenvironmentalistsopposewind○Tosuggestthatwindturbinesresultinrelativelyfewbird千万不要去定位找numbers。我们从上往下读，当读到some ystsalso......的时候，有一个最关键的dwarfed，就是侏儒的意思。dwarfedby相形见绌。Paragraph4:Reductioninnumbersofgameshouldhavebodedillfortheirsurvivalinlatertimes.Aworseningoftheplightofdeerwastobeexpectedassettlersencroachedontheland,logging,burning,andclearing,eventuallyrecingawildernesslandscapewithroads,cities,towns,andfactories.doubtthenumbersofdeerdeclinedstillfurther.RecallthefateoftheColumbianwhite-taileddeer,nowinaprotectedstatus.Butfortheblack-taileddeer,humanpressurehashadjusttheoppositeeffect.WildlifezoologistHelmutBuechner(1953),inreviewingthenatureofbioticchangesinWashingtonthroughrecordedtime,saysthat"sincetheearly1940s,thestatehashadmoredeerthanatanyothertimeinitshistory,thewinterpopulationfluctuatingaroundapproximay320,000deer(muleandblack-taileddeer),whichwillyieldabout65,000ofeitherandanyageannuallyforanindefiniteperiod."Whydoestheauthoraskreaderstorecall“thefateoftheColumbianwhite-taileddeer”inthediscussionofchangesinthewildernesslandscape?○Toprovidesupportfortheideathathabitatdestructionwouldleadtopopulationdecline○Tocomparehowtwospeciesofdeercausedbioticchangesinthewilderness○Toprovideanexampleofaspeciesofdeerthathassuccessfullyadaptedtohumansettlement○ToarguethatsomedeerspeciesmustbegivenaprotectedshouldhavedonebodeillworseningD错，讲被保护，不是为了证明被保护，而是为了证明数量少。A。接着，but出现，转折oppositeeffectmoredeer——相反的情况，转折前是butParagraph3:Thesubjectsofthepaintingsaremostlyanimals.Thepaintingsrestonbarewalls,withnobackdropsorenvironmentaltraps.Perhaps,likemanycontemporarypeoples,UpperPaleolithicmenandwomenbelievedthatthedrawingofahumanimagecouldcausedeathorinjury,andifthatwereindeedtheirbelief,itmightexinwhyhumanfiguresarerarelydepictedincaveart.Anotherexnationforthefocusonanimalsmightbethatthesepeoplesoughttoimprovetheirluckathunting.Thistheoryissuggestedbyevidenceofchipsinthepaintedfigures,perhapsmadebyspearsthrownatthedrawings.Butifimprovingtheirhuntingluckwasthechiefmotivationforthepaintings,itisdifficulttoexinwhyonlyafewshowsignsofhavingbeenspeared.Perhapsthepaintingswereinspiredbytheneedtoincreasethesupplyofanimals.CaveartseemstohavereachedapeaktowardtheendoftheUpperPaleolithicperiod,whentheherdsofgameweredecreasing.WhydoestheauthormentionthatUpperPaleolithiccaveartseemedtohave“reachedapeaktowardtheendoftheUpperPaleolithicperiod,whentheherdsofgameweredecreasing”?○ToarguethatUpperPaleolithicartceasedtoincludeanimalswhenherdsofgamebecamescarce○Toprovidesupportfortheideathattheaimofthepaintingswastoincreasethesupplyofanimalsforhunting○ToemphasizetheimprovementinthequalityofcaveartthroughouttheUpperPaleolithicperiod○ToshowthedirectconnectionbetweenthedecreaseinherdsofgameandtheendoftheUpperPaleolithicperiod顺序读下来，读到itis （but后），从这里开始有中心词supplyofanimalsParagraph5:Scientistshaveknownforsometimethatcertainnts,calledhyperaccumulators,canconcentratemineralsatlevelsahundredfoldorgreaterthannormal.Asurveyofknownhyperaccumulatorsidentifiedthat75percentofthemamassednickel,cobalt,copper,zinc,manganese,lead,andcadmiumareothermineralsofchoice.Hyperaccumulatorsruntheentirerangeofthentworld.Theymaybeherbs,shrubs,ortrees.Manymembersofthemustardfamily,spurgefamily,legumefamily,andgrassfamilyaretophyperaccumulators.Manyarefoundintropicalandsubtropicalareasoftheworld,whereaccumulationofhighconcentrationsofmetalsmayaffordsomeprotectionagainstnt-eatinginsectsandmicrobialpathogens.Whydoestheauthormention“herbs”,“shrubs”,andToprovideexamplesofnttypesthatcannottoleratehighlevelsofharmfulToshowwhysomanyntsareTohelpexinwhyhyperaccumulatorscanbefoundinsomanydifferentToemphasizethathyperaccumulatorsoccurinawiderange ntParagraphOnlyrecentlyhaveinvestigators

using tocleanusing withntingofhyperaccumulatingspeciesintheandwastesitesthathavebeencontaminatedbytoxiclevelsofheavymetals–anenvironmentallywithntingofhyperaccumulatingspeciesinthearea,suchasanabandonedmineoranirrigationpondcontaminatedbyrunoff.Toxicmineralswouldfirstbeabsorbedbyrootsbutlaterrelocatedtothestemandleaves.Aharvestoftheshootswouldremovethetoxiccompoundsoffsitetobeburnedorcompostedtorecoverthemetalforindustrialuses.Afterseveralyearsofcultivationandharvest,thesitewouldberestoredatacostmuchlowerthanthepriceofexcavationandreburial,thestandardpracticeforremediationofcontaminatedsoils.Forexamples,infieldtrials,thentalpinepennycressremovedzincandcadmiumfromsoilsnearazincsmelter,andnmustard,nativetoPakistanand ,hasbeeneffectiveinreducinglevelsofseleniumsaltsby50percentincontaminatedsoils.Whydoestheauthormention nTowarnaboutpossiblerisksinvolvedinTohelpillustratethepotentialofToshowthathyperaccumulatingntsgrowinmanyregionsoftheToexinhowzinccontaminationcanbeForexample举例，就一定是为了证明前面的。成本更低-更有优势--B。ParagraphIn1831whenSmithwasfinallyrecognizedbytheGeologicalSocietyofLondonasthe“fatherofEnglishgeology,”itwasnotonlyforhismapsbutalsoforsomethingevenmoreimportant.Eversincepeoplehadbeguntocatalogthestratainparticularoutcrops,therehadbeenthehopethatthesecouldsomehowbeusedtocalculategeologicaltime.Butasmoreandmoreaccumulationsofstratawerecatalogedinmoreandmoreces,itbecameclearthatthesequencesofrockssometimesdifferedfromregiontoregionandthatnorocktypewasevergoingto eareliabletimemarkerthroughouttheworld.Evenwithouttheproblemofregionaldifferences,rockspresentadifficultyasuniquetimemarkers.Quartzisquartz—asiliconionsurroundedbyfouroxygenions—there’snodifferenceatallbetweentwo-million-year-oldPleistocenequartzandCambrianquartzcreatedover500millionyearsago.Whydoestheauthorusethephrase“Quartzis○TodescribehowthedifferencesbetweenPleistoceneandCambrianquartzrevealinformationaboutdatingrocks○Topointoutthatthechemicalcompositionofquartzmakesitmoredifficulttodatethanotherrocks○ToprovideanexampleofhowregionaldifferencesinrocksequencescanmakeaparticularrockdifficulttodateToexinthatrocksaredifficulttousefordatingbecausetheirchemicalcompositionsalwaysremainthesameovertimeParagraph2:Howmightthisinabilitytorecallearlyexperiencesbeexined?Thesheerpassageoftimedoesnotaccountforit;adultshaveexcellentrecognitionofpicturesofpeoplewhoattendedhighschoolwiththem35yearsearlier.Anotherseeminglyusibleexnation—thatinfantsdonotformenduringmemoriesatthispointindevelopment—alsoisincorrect.Childrentwoandahalftothreeyearsoldrememberexperiencesthatoccurredintheirfirstyear,andelevenmontholdsremembersomeeventsayearlater.Nordoesthehypothesisthatinfantileamnesiareflectsrepression—orholdingback—ofuallychargedepisodesexinthephenomenon.Whilesuchrepressionmayoccur,peoplecannotrememberordinaryeventsfromtheinfantandtoddlerperiodseither.1.Whatpurposedoesparagraph2serveinthelargerdiscussionofchildren’sinabilitytorecallearlyexperiences?○Toarguethattheoriesthatarenotsubstantiatedbyevidenceshouldgenerallybeconsideredunreliable○Toarguethatthehypothesesmentionedinparagraph2havebeenmorethoroughlyresearchedthanhavethetheoriesmentionedlaterinthepassage○Toexinwhysometheoriesaboutinfantileamnesiaarewrongbeforepresentingonesmorelikelytobetrue○ToexinwhyinfantileamnesiaisofgreatinteresttoParagraph2:OutflowchannelsareprobablyrelicsofcatastrophicfloodingonMarslongago.Theyappearonlyinequatorialregionsandgenerallydonotformextensiveinterconnectednetworks.Instead,theyareprobablythepathstakenbyhugevolumesofwaterdrainingfromthesouthernhighlandsintothenorthernins.Theonrushingwaterarisingfromtheseflashfloodslikelyalsoformedtheoddteardrop-shaped“islands”(resemblingtheminiatureversionsseeninthewetsandofourbeachesatlowtide)thathavebeenfoundontheinsclosetotheendsoftheoutflowchannels.Judgingfromthewidthanddepthofthechannels,theflowratesmusthavebeenenormous—perhapsasmuchasahundredtimesgreaterthanthe105tonspersecondcarriedbythegreatAmazonriver.Floodingshapedtheoutflowchannelsapproximay3billionyearsago,aboutthesametimesasthenorthernvolcanicinsformed.5.Inparagraph2,whydoestheauthorincludetheinformationthat105tonsofwaterflowthroughtheAmazonriverpersecond?○ToemphasizethegreatsizeofthevolumeofwaterthatseemstohaveflowedthroughMars’outflowchannels○ToindicatedatausedbyscientiststoestimatehowlongagoMars’outflowchannelswereformed○ToarguethatflashfloodsonMarsmayhavebeenpowerfulenoughtocausetear-shaped“islands”toform○ToarguethattheoffloodwatersonMarswaspowerfulenoughtoshapethenorthernvolcanic 没有forexample，为了确保万无一失 一句的enormous在本句找到greatergreater、enormousgreat，感觉就会更加强烈】Paragraph4:Morerecentgeologicstudieseddeglaciationandtheexistenceofice-areasthroughoutmajorcoastalareasofBritishColumbia,Canada,by13,000yearsago.ResearchnowindicatesthatsizableareasofsoutheasternAlaskaalongtheinnercontinentalshelfwerenotcoveredbyicetowardtheendofthelastIceAge.Onestudysuggeststhatexceptfora250-coastalareabetweensouthwesternBritishColumbiaandWashingtonState,theNorthwestCoastofNorthAmericawaslargelyoficebyapproximay16,000yearsago.Vastareasalongthecoastmayhavebeendeglaciatedbeginningaround16,000yearsago,possiblyprovidingacoastalcorridorforthemovementofnts,animals,andhumanssometimebetween13,000and14,000yearsago.Theauthor'spurposeinparagraph4isindicatethatanumberofrecentgeologicstudiesseemtoprovidesupportforthecoastalhypothesis exinwhyhumansmayhavereachedAmerica'snorthwestcoastbeforeanimalsandntsdidshowthatthecoastalhypothesismayexinhowpeoplefirstreachedAlaskabutitcannotexinhowpeoplereachedareaslikemodernBritishColumbiaandWashingtonStateonestudy来证明】Paragraph4:Manymillionsofyearsafterfernsevolved(butlongbeforetheHawaiianIslandswerebornfromthesea),anotherkindoffloraevolvedonEarth:theseed-bearingnts.Thiswasawonderfulbiologicalinvention.Theseedhasanoutercoatingthatsurroundsthegeneticmaterialofthenewnt,andinsidethiscoveringisaconcentratedsupplyofnutrients.Thustheseed’schancesofsurvivalaregreatlyenhancedoverthoseofthenakedspore.Onetypeofseed-bearingnt,theangiosperm,includesallformsofbloomingvegetation.Intheangiospermtheseedsarewrappedinanadditionallayerofcovering.Someofthesecoatsarehard–likethesofanut–forextraprotection.Somearesoftandtempting,likeapeachoracherry.Insomeangiospermstheseedsareequippedwithgossamerwings,likethedandelionandmilkweedseeds.Thesenewcharacteristicsofferedbetterwaysfortheseedtomovetonewhabitats.Theycouldtravelthroughtheair,floatinwater,andliedormantformanymonths.Whydoestheauthormention“anut”,“apeach”,and“aToindicatethatsomeseedsarelesslikelytosurvivethanTopointoutthatmanyangiospermscanbeToprovideexamplesofbloomingToillustratethevarietyofcoveringsamongangiospermtheseseeds...layerofcoveringDParagraph2:Howarewetounderstandtheirdifferentfeedingpreferences?Theanswerliesintwoassociateddifferencesamongthespecies,intheirdigestivesystemsandbodysizes.Accordingtotheirdigestivesystems,theseherbivorescanbedividedintotwocategories:thenonruminants(suchasthezebra,whichhasadigestivesystemlikeahorse)andtheruminants(suchasthewildebeest,topi,andgazelle,whicharelikethecow).Nonruminantscannotextractmuchenergyfromthehardpartsofant;however,thisismorethanmadeupforbythefastspeedatwhichfoodpassesthroughtheirguts.Thus,whenthereisonlyashortsupplyofpoor-qualityfood,thewildebeest,topi,andgazelleenjoyanadvantage.Theyareruminantsandhaveaspecialstructure(therumen)intheirstomachs,whichcontainsmicroorganismsthatcanbreakdownthehardpartsofnts.Foodpassesonlyslowlythroughtheruminant’sgutbecauseruminating—digestingtheparts—takestime.Theruminantcontinuallyregurgitatesfoodfromitsbacktoitsmouthtochewitupfurther(thatiswhatacowis ngwhen“chewingcud”).Onlywhenithasbeenchewedupanddigestedalmosttoaliquidcanthefoodpassthroughtherumenandonthroughthegut.Largerparticlescannotpassthroughuntiltheyhavebeencheweddowntosize.Therefore,whenfoodisinshortsupply,aruminantcanlastlongerthananonruminantbecauseitcanderivemoreenergyoutofthesamefood.ThedifferencecanpartiallyexintheeatinghabitsoftheSerengetiherbivores.Thezebrachoosesareaswherethereismorelow-qualityfood.Itmigratesfirsttounexploitedareasandchompstheabundantlow-qualitystemsbeforemovingon.Itisafast-in/fast-outfeeder,relyingonahighoutputofpleydigestedfood.Bythetimethewildebeests(andotherruminants)arrive,thegrazingandtramplingofthezebraswillhavewornthevegetationdown.Astheruminantsthensettowork,theyeatdowntothelower,leafierpartsofthevegetation.AllofthisfitsinwiththedifferencesincontentswithwhichweTheauthormentionsthecowandthehorseinparagraph2inorderdistinguishthefuncti