雅思索試閱讀模擬試題(含答案)1There'sadimmer

\o"switch???????"switch

insidethesunthatcausesitsbrightnesstoriseandfallontimescalesofaround100,000years—exactlythesameperiodasbetweeniceagesonEarth.Sosaysaphysicistwhohascreatedacomputermodelofourstar's

\o"core???????"core.2RobertEhrlichofGeorge

\o"Mason???????"Mason

UniversityinFairfax,Virginia,modelledtheeffectof

\o"temperature???????"temperaturefluctuationsinthesun'sinterior.Accordingtothestandardview,thetemperatureofthesun's

\o"core???????"core

isheld

\o"constant???????"constant

bythe

\o"opposing???????"opposing

pressuresof

\o"gravity???????"gravityandnuclear

\o"fusion???????"fusion.However,Ehrlichbelievedthat

\o"slight???????"slight

variationsshouldbepossible.3HetookashisstartingpointtheworkofAttilaGrandpierreoftheKonkoly

\o"Observatory???????"Observatory

oftheHungarian

\o"Academy???????"Academy

ofSciences.In,Grandpierreanda

\o"collaborator???????"collaborator,Gáborágoston,\o"calculated???????"calculated

that

\o"magnetic???????"magnetic

fieldsinthesun's

\o"core???????"core

could

\o"produce???????"produce

smallinstabilitiesinthesolarplasma.Theseinstabilitieswould

\o"induce???????"induce

localisedoscillationsin

\o"temperature???????"temperature.4Ehrlich'smodelshowsthatwhilstmostoftheseoscillationscanceleachotherout,some\o"reinforce???????"reinforce

oneanotherandbecomelong-lived

\o"temperature???????"temperature

variations.Thefavouredfrequenciesallowthesun's

\o"core???????"core

\o"temperature???????"temperature

to

\o"oscillate???????"oscillate

arounditsaveragetemperatureof13.6millionkelvinincycles

\o"lasting???????"lasting

either100,000or41,000years.Ehrlichsaysthat

\o"random???????"random

interactionswithinthesun's

\o"magnetic???????"magnetic

fieldcould

\o"flip???????"flip

thefluctuationsfromonecyclelengthtotheother.5ThesetwotimescalesareinstantlyrecognisabletoanyonefamiliarwithEarth'siceages:forthepastmillionyears,iceageshaveoccurredroughlyevery100,000years.Beforethat,theyoccurredroughlyevery41,000years.6Mostscientistsbelievethattheiceagesaretheresultof

\o"subtle???????"subtle

changesinEarth'sorbit,knownastheMilankovitchcycles.OnesuchcycledescribesthewayEarth'sorbitgraduallychangesshapefroma

\o"circle???????"circle

toa

\o"slight???????"slight

\o"ellipse???????"ellipse

andbackagainroughlyevery100,000years.Thetheorysaysthisalterstheamountofsolar

\o"radiation???????"radiation

thatEarthreceives,triggeringtheiceages.However,a

\o"persistent???????"persistent

problemwiththistheoryhasbeenits

\o"inability???????"inability

toexplainwhytheiceageschanged

\o"frequency???????"frequency

amillionyearsago.7"InMilankovitch,thereiscertainlynogoodideawhythe

\o"frequency???????"frequency

shouldchangefromonetoanother,"saysNeilEdwards,aclimatologistattheOpenUniversityinMiltonKeynes,UK.Noristhe

\o"transition???????"transition

problemtheonlyonetheMilankovitchtheoryfaces.Ehrlichandothercritics\o"claim???????"claim

thatthe

\o"temperature???????"temperature

variationscausedbyMilankovitchcyclesaresimplynotbigenoughtodriveiceages.8However,EdwardsbelievesthesmallchangesinsolarheatingproducedbyMilankovitchcyclesarethen

\o"amplified???????"amplified

byfeedbackmechanismsonEarth.Forexample,ifseaicebeginstoformbecauseofa

\o"slight???????"slight

cooling,carbondioxidethatwouldotherwisehavefounditswayintotheatmosphereaspartofthecarboncycleislockedintotheice.Thatweakensthe

\o"greenhouse???????"greenhouseeffectandEarthgrowsevencolder.9AccordingtoEdwards,thereisnolackofsuchmechanisms."Ifyouaddtheireffectstogether,thereismorethanenoughfeedbacktomakeMilankovitchwork,"hesays."Theproblemnowisidentifyingwhichmechanismsareatwork."ThisiswhyscientistslikeEdwardsarenotyetreadytogiveuponthe

\o"current???????"current

theory."Milankovitchcyclesgiveusiceagesroughlywhenwe

\o"observe???????"observe

themtohappen.Wecan

\o"calculate???????"calculate

whereweareinthecycleandcompareitwith

\o"observation???????"observation,"hesays."Ican'tseeanywayoftesting[Ehrlich's]ideatoseewhereweareinthe

\o"temperature???????"temperature

\o"oscillation???????"oscillation."10Ehrlichconcedesthis."Ifthereisawaytotestthistheoryonthesun,Ican'tthinkofonethatispractical,"hesays.That'sbecause

\o"variation???????"variation

over41,000to100,000yearsistoogradualtobeobserved.However,theremaybeawaytotestitinotherstars:reddwarfs.Theircoresaremuchsmallerthanthatofthesun,andsoEhrlichbelievesthatthe

\o"oscillation???????"oscillation

periodscouldbeshortenoughtobeobserved.Hehasyetto

\o"calculate???????"calculate

the

\o"precise???????"precise

periodorthe

\o"extent???????"extent

of\o"variation???????"variation

inbrightnesstobeexpected.11NigelWeiss,asolarphysicistattheUniversityofCambridge,isfarfrom

\o"convinced???????"convinced.HedescribesEhrlich'sclaimsas"utterly

\o"implausible???????"implausible".EhrlichcountersthatWeiss'sopinionisbasedonthestandardsolarmodel,whichfailstotakeintoaccountthe

\o"magnetic???????"magnetic

instabilitiesthatcausethe

\o"temperature???????"temperature

fluctuations.(716words)Questions1-4CompleteeachofthefollowingstatementswithOneorTwonamesofthescientistsfromtheboxbelow.Writethe

\o"appropriate???????"appropriate

lettersA-Einboxes1-4onyouranswersheet.A.AttilaGrandpierreB.GáborágostonC.NeilEdwardsD.NigelWeissE.RobertEhrlich1....claimsthere抯adimmer

\o"switch???????"switch

insidethesunthatcausesitsbrightnesstoriseandfallinperiodsaslongasthosebetweeniceagesonEarth.2....\o"calculated???????"calculated

thatthe

\o"internal???????"internal

solar

\o"magnetic???????"magnetic

fieldscould

\o"produce???????"produce

instabilitiesinthesolarplasma.3....holdsthatMilankovitchcyclescan

\o"induce???????"induce

changesinsolarheatingonEarthandthechangesare

\o"amplified???????"amplified

onEarth.4....doesn'tbelieveinEhrlich'sviewpointsatall.Questions5-9Dothefollowingstatementsagreewiththeinformationgiveninthereadingpassage?Inboxes5-9onyouranswersheetwriteTRUEifthe

\o"statement???????"statement

istrueaccordingtothepassageFALSEifthe

\o"statement???????"statement

isfalseaccordingtothepassageNOTGIVENiftheinformationisnotgiveninthepassage5.Theiceageschanged

\o"frequency???????"frequency

from100,000to41,000yearsamillionyearsago.6.ThesoleproblemthattheMilankovitchtheorycannot

\o"solve???????"solve

istoexplainwhytheiceage\o"frequency???????"frequency

should

\o"shift???????"shift

fromonetoanother.7.Carbondioxidecanbelockedartificiallyintoseaiceto

\o"eliminate???????"eliminate

the

\o"greenhouse???????"greenhouse

effect.8.SomescientistsarenotreadytogiveuptheMilankovitchtheorythoughthey

\o"haven???????"haven'tfiguredoutwhichmechanisms

\o"amplify???????"amplify

thechangesinsolarheating.9.BothEdwardsandEhrlichbelievethatthereisnopracticalwaytotestwhenthesolar\o"temperature???????"temperature

\o"oscillation???????"oscillation

beginsandwhenends.Questions10-14Completethenotesbelow.Chooseone

\o"suitable???????"suitable

wordfromtheReadingPassageaboveforeachanswer.Writeyouranswersinboxes10-14onyouranswersheet.Thestandardviewassumesthatthe

\o"opposing???????"opposing

pressuresof

\o"gravity???????"gravity

andnuclearfusionsholdthe

\o"temperature???????"temperature

...10...inthesun'sinterior,butthe

\o"slight???????"slight

changesintheearth's...11...\o"alter???????"alter

thetemperatureontheearthandcauseiceagesevery100,000years.ABritishscientist,however,challengesthisviewbyclaimingthatthe

\o"internal???????"internal

solar

\o"magnetic???????"magnetic

...12...can

\o"induce???????"inducethe

\o"temperature???????"temperature

oscillationsinthesun’sinterior.Thesun's

\o"core???????"core

temperatureoscillatesarounditsaveragetemperaturein...13...

\o"lasting???????"lasting

either100,000or41,000years.Aeractionswithinthesun'smagneticfieldcould

\o"flip???????"flip

thefluctuationsfromonecyclelengthtotheother,whichexplainswhytheiceageschanged

\o"frequency???????"frequency

amillionyearsago.Answerkeysandexplanations:1.ESeethesentencesinparagraph1(There'sadimmer

\o"switch???????"switch

insidethesunthatcausesitsbrightnesstoriseandfallontimescalesofaround100,000years—exactlythesameperiodasbetweeniceagesonEarth.Sosaysaphysicistwhohascreatedacomputermodelofourstar's

\o"core???????"core.)andpara.2(RobertEhrlichofGeorge

\o"Mason???????"Mason

UniversityinFairfax,Virginia,modelledtheeffectof

\o"temperature???????"temperaturefluctuationsinthesun'sinterior.)2.ABSeepara.3:?istyle=’\o"normal???????"normal’>Grandpierreanda

\o"collaborator???????"collaborator,Gáborágoston,

\o"calculated???????"calculatedthat

\o"magnetic???????"magnetic

fieldsinthesun's

\o"core???????"core

could

\o"produce???????"produce

smallinstabilitiesinthesolarplasma.3.CSeepara.8:EdwardsbelievesthesmallchangesinsolarheatingproducedbyMilankovitchcyclesarethen

\o"amplified???????"amplified

byfeedbackmechanismsonEarth.4.DSeepara.11:NigelWeiss,asolarphysicistattheUniversityofCambridge,isfarfrom\o"convinced???????"convinced.HedescribesEhrlich’sclaimsas"utterly

\o"implausible???????"implausible".5.FalseSeepara.5:forthepastmillionyears,iceageshaveoccurredroughlyevery100,000years.Beforethat,theyoccurredroughlyevery41,000years.6.FalseSeepara.7:"InMilankovitch,thereiscertainlynogoodideawhythe

\o"frequency???????"frequency

shouldchangefromonetoanother,"...Noristhe

\o"transition???????"transition

problemtheonlyonetheMilankovitchtheoryfaces.7.NotGivenSeepara.8:ifseaicebeginstoformbecauseofa

\o"slight???????"slight

cooling,carbondioxide?islockedintotheice.Thatweakensthe

\o"greenhouse???????"greenhouse

effect.(Thepassagedoesn抰mentionanythingaboutlockingCo2intoiceartificially.)8.TrueSeepara.9:thereisnolackofsuchmechanisms."Ifyouaddtheireffectstogether,thereismorethanenoughfeedbacktomakeMilankovitchwork,"?"Theproblemnowisidentifyingwhichmechanismsareatwork."ThisiswhyscientistslikeEdwardsarenotyetreadytogiveuponthe\o"current???????"current

theory.9.TrueSeethesentencesinpara.9(AccordingtoEdwards,卙esays."Ican'tseeanywayoftesting[Ehrlich's]ideatoseewhereweareinthe

\o"temperature???????"temperature

\o"oscillation???????"oscillation.")andpara.10(Ehrlichconcedesthis."Ifthereisawaytotestthistheoryonthesun,Ican’tthinkofonethatispractical).10.constantSeepara.2:Accordingtothestandardview,the

\o"temperature???????"temperature

ofthesun's

\o"core???????"core

isheld\o"constant???????"constant

bythe

\o"opposing???????"opp