ThermalStratification
Paragraph1
Physicalcharacteristicsofaquaticenvironmentsatdifferentdepthssuchassaltlevel,light,inorganicnutrients,degreeofacidity,andpressureallplaykeyrolesinthedistributionoforganisms.Oneofthemostimportantphysicalfeaturesisthermalstratification.
Paragraph2
Whensolarradiationstrikeswater,someisreflected,butmostpenetratesthesurfaceandisultimatelyabsorbed.Althoughwatermayappeartransparent,itismuchdenserthanairandabsorbsradiationrapidnclearwater,99percentofthesolarradiationisabsorbedintheupper50to100meters.Longerwavelengthsoflightareabsorbedfirst;theshorterwavelengths(whichhavemoreenergy)penetratefarther,givingthedepthstheircharacteristicbluecolor.1.A.B.C.D.
Thewordultimatelyinthepassageisclosestinmeaningtoprobablyquicklyeventuallyfrequently
2.Accordingtoparagraph2,whichofthefollowingistrueaboutsolarradiationwhenitstrikeswater
A.Longerwavelengthstravelfarther.B.Mostofitisabsorbednearthesurface.C.Itisnotabsorbedbycloudywater.
D.Morelongwavelengthsthanshortwavelengthsareabsorbed.
Paragraph3
Thisrapidabsorptionofsunlightbywaterhastwoimportantconsequences.First,itmeansthatphotosynthesistheprocessbywhichplantsusetheenergyofsunlighttoproducetheorganiccarboncompoundsnecessaryforlifecanonlyoccurinsurfacewaterswherethelightintensityissufficientlyhigh.Speciesthatproducetheirownorganiccarboncompoundsarecalledprimaryproducers,andtheyarethebaseofthemarinefoodweb.Virtuallyallofthephotosynthesisthatsupportstherichlifeofoceansandlakescomesfromplantslivingintheupper10to30metersofwater.Alongshoresandinveryshallowbodiesofwater,somespeciessuchaskelparerootedtothebottom.Theseplantsmayattainconsiderablesizeandstructuralcomplexity,andmaysupportdiversecommunitiesoforganisms.Intheopenwatersthatcovermuchoftheglobe,however,theprimaryproducersoforganiccarbonaretiny,oftenone-celledalgae(calledphytoplankton),whicharesuspendedinthewater.
195Zooplankton,tinyinvertebratesthatfeedonphytoplankton,migrateverticallyonadailycycle:upintothesurfacewatersatnighttofeedanddownintothedark,deeperwatersduringthedaytoescapepredatoryfishthatrelyonlighttodetectprey.3.A.B.C.D.
ThewordvirtuallyinthepassageisclosestinmeaningtoApparentlyUsuallyNearlyFortunately
4.Accordingtoparagraph3,allofthefollowingaretrueofkelpEXCEPT:A.Theyarefoundatthebottomofshallowwaters.B.Theyaretheprimaryproducersoforganiccarbon.C.Theycangrowverylarge.
D.Theyareasourceoffoodforavarietyoforganisms.5.ThewordsuspendedinthepassageisclosestinmeaningtoA.dissolvedB.floatingC.invisibleD.released
6.Whichofthesentencesbelowbestexpressestheessentialinformationinthehighlightedsentenceinthepassage?Incorrectchoiceschangethemeaninginimportantwaysorleaveoutessentialinformation.
A.Zooplanktonmoveupintosurfacewatersatnighttofeedonphytoplankton,anddownintodeep,darkwatersindaytimetoavoiddetectionbypredatoryfish.
B.Zooplanktonmigrateverticallyonadailybasisinordertofeedonphytoplankton,followingthemupintosurfacewatersbydayanddownintodark,deeperwatersatnight.
C.Unlikezooplankton,whichmigratebetweensurfacewatersanddeeperwaters,predatoryfishmustrelyonthedaytimelightofsurfacewaterstodetectprey.
D.Zooplanktonaresotinythattheycanonlybedetectedbypredatoryfishinthelightconditionsofsurfacewater,wheretheyfeedonphytoplankton.
Paragraph4
Second,therapidabsorptionofsunlightbywatermeansthatonlysurfacewaterisheated.Thedensityofpurewaterisgreatestat4degreesanddeclinesasthewater'stemperaturerisesaboveorfallsbelowthispoint.Whensolarradiationheatsthewatersurfaceabove4¡ãC,thewarmsurfacewaterbecomeslighterthanthecool,deeperwater,andsotendstoremainonthesurface,whereitmaybeheatedfurtherandbecomeevenlessdense.Intropicalareasandintemperateclimatesduringthesummer,thesurfacesofoceansandlakesareusuallycoveredbyathinlayerofwarm
196water.Unlessthesebodiesofwaterareshallow,thedeepwaterbelowthislayerismuchcolder(sometimesnear4degrees).Thechangeintemperaturebetweenthewarmsurfacewaterandthecold,deepwateriscalledthethermocline.Mixingofthesurfacewaterbywaveactiondeterminesthedepthofthethermoclineandmaintainsrelativelyconstanttemperaturesinthewateraboveit.
7.Accordingtoparagraph4,whatisathermocline
A.Thedeep,coldlayerofwaterbelowthesurfaceofoceansandlakesB.ThethinlayerofwarmwateronthesurfaceofoceansandlakesC.Thechangeindensityofsurfacewaterasitiscontinuallyheated
D.Thepointatwhichthetemperatureofwaterinoceansandlakeschangesfromwarmtocold
Paragraph5
Tropicallakesandoceansshowpronouncedpermanentstratificationoftheirphysicalproperties,withwarm,well-oxygenated,andlightedsurfacewatergivingwaytofrigid,dark,deepwateralmostdevoidofoxygen.Oxygencannotbereplenishedatgreatdepthswheretherearenophotosyntheticorganismstoproduceit,andthestablethermalstratificationpreventsmixingandreoxygenationbysurfacewater.Onlyrelativelyfeworganismscanliveinsuchextremeconditions.Thewasteproductsanddeadbodiesoforganismslivinginthesurfacewaterssinktothedepths,takingtheirmineralnutrientswiththem.Thelackofverticalcirculationthuslimitsthesupplyofnutrientstothephytoplanktonabove.Consequently,deeptropicallakesareoftenrelativelyunproductiveanddependoncontinuedinputfromstreamsforthenutrientsrequiredtosupportlife.
8.ThewordreplenishedinthepassageisclosestinmeaningtoA.absorbedB.restoredC.containedD.obtained
9.Accordingtoparagraph5,allofthefollowingaretrueofthewateratgreatdepthsintropicallakesEXCEPT:
A.Ithaslessoxygenthanthesurfacewaterdoes.B.Itisverydark.
C.Itcontainsrelativelyfewlivingorganisms.D.Ithaslowlevelsofmineralnutrients.
Paragraph6
Thesituationissomewhatdifferentintemperateandpolarwaters.Deeplakes,inparticular,undergodramaticseasonalchanges:theydevelopwarmsurfacetemperaturesandapronouncedthermoclineinsummer,butfreezeoverinwinter.Twiceeachyear,inspringandfall,theentirewatercolumnattainsequaltemperature
197andequaldensity;moderatewindsmaythengeneratewavesthatmixdeepandshallowwater,producingwhatiscalledoverturn.Thissemiannualmixingcarriesoxygendownwardandreturnsinorganicnutrientstothesurface.Phosphorusandothernutrientsmaybedepletedduringthesummer;overturnreplenishesthesenutrientsbystimulatingthegrowthofphytoplankton.10.TheworddramaticinthepassageisclosestinmeaningtoA.partialB.complexC.frequentD.striking
11.Accordingtoparagraph6,afteroverturn,deepwaterlevelsoflakesintemperateclimateswillcontainincreasedamountsofA.warmwaterB.phosphorusC.oxygen
D.phytoplankton
12.Accordingtoparagraphs5and6,temperatelakesareingeneralmoreproductivethantropicallakesbecause
A.temperatelakesreceivemorenutrientsfromincomingstreamsB.thesummerthermoclineisrelativelydeepintemperatelakesC.solarradiationpenetratesmoreofthewaterintemperatelakesD.temperatelakesexperienceverticalcirculationofwater
Paragraph2
Whensolarradiationstrikeswater,someisreflected,butmostpenetratesthesurfaceandisultimatelyabsorbed.[A]Althoughwatermayappeartransparent,itismuchdenserthanairandabsorbsradiationrapidly.[B]Inclearwater,99percentofthesolarradiationisabsorbedintheupper50to100meters.[C]Longerwavelengthsoflightareabsorbedfirst;theshorterwavelengths(whichhavemoreenergy)penetratefarther,givingthedepthstheircharacteristicbluecolor.[D]
13.Lookatthefoursquaresthatindicatewherethefollowingsentencecouldbeaddedtothepassage.
Ifthewateriscloudedbymanymicroscopicorganisms,absorptionoccursevenclosertothesurface.
Wherewouldthesentencebestfit?Clickonasquaretoaddthesentencetothepassage.
14.Dragyourchoicestothespaceswheretheybelong.Toreviewthepassage,clickonViewText.AnswerChoices
198A.Sunlightisrapidlyabsorbedbytheupperlayerofwater,whichmakesitwarmerandconsequentlylessdensethanthewaterbelow.
B.Photosynthesizingplants,whichprovidethefoodandoxygenformostotherformsofaquaticlife,arelimitedtothelevelsofoceansandlakeswheresunlightisavailable.
C.Thediversityofplantlifeinshallowwatermakesitattractivetozooplankton.
D.Aswaterbecomeslessdenseandmovestothesurfaceoftheoceanorlake,itcoolsdownandmoderatesthetemperatureofthesurface.
E.Becausemoresolarenergyisabsorbedbybodiesofwaterinthetropics,thetopmostlayerofthethermoclineiswidestthere.
F.Inthetropics,permanentthermalstratificationlimitstheamountoflifesupportedindeepbodiesofwater;however,intemperateclimates,seasonalthermalstratificationallowsverticalcirculationandmixingofwater,allowingthesupportofmorelife.
Live Performance
Paragraph 1
Unlike video and cinema (although sometimes employing elements of both), the theater is a living, real-time event, with both performers and audience mutually interacting, each aware of the other's immediate presence. This turns out to be an extremely important distinction. Distinguished film stars, particularly those with theater backgrounds (as most have), routinely return to the live dramatic stage despite the substantially greater financial rewards of film work and invariably prefer stage acting because of the immediate audience response theater provides, with its corresponding sensations of excitement and presence.1. The word distinction in the passage is closest in meaning toA.ideaB.blendC.definitionD.difference
2.Paragraph1makeswhichofthefollowingpointsabouttheaterandfilmA.Theateraudiencestendtobemorecriticalthanfilmaudiences.B.Actorsinthetheaterareusuallynotaswell-knownasfilmactors.
C.Theatercompaniestendtopaymorethanfilmcompaniesdoforthemostdistinguishedactors.
D.Audiencesrespondtoactorsdifferentlyintheaterthaninfilm.
3.Paragraph1suggeststhatthereasondistinguishedfilmstarsreturntolivetheateristhatthey
A.areabletocommandhigherfeesaswell-knownactors
199B.enjoytheexcitementofperformingbeforealiveaudienceC.havegreatrespectfortheatricaldramaasanartform
D.aredissatisfiedwiththerolestheyareofferedinfilmsandtelevision
Paragraph2
Thefirstoftheseistherapportexistingbetweenactorandaudience.[A]Botharebreathingthesameair;bothareinvolvedatthesametimeandinthesamespacewiththestagelifedepictedbytheplay.[B]Sometimestheirmutualfascinationisalmostpalpable;everyactor'sperformanceisaffectedbythewaytheaudienceyieldsorwithholdsitsresponses:itslaughter,sighs,applause,gasps,silences.[C]Livetheatricalperformanceisalwaysatwo-waycommunicationbetweenstageandhouse.[D]
4.ThewordrapportinthepassageisclosestinmeaningtoA.excitementB.balanceC.bond
D.fascination
Paragraph3
Second,theatercreatesarelationshipamongtheaudiencemembers.Havingarrivedatthetheatersasindividualsoringroupsoftwoorthree,theaudiencemembersquicklyfindthemselvesfusedintoacommonexperiencewithtotalstrangers:laughingatthesamejokes,empathizingwiththesamecharacters,experiencingthesamerevelations.Thisbroadcommunalresponseisneverdevelopedbytelevisiondrama,whichisplayedchieflytosolitaryorclusteredviewerswho(becauseoffrequentcommercialadvertisements)areonlyintermittentlyengaged,norisitlikelytohappeninmoviehouses,whereaudiencemembersessentiallyassumeaone-on-onerelationshipwiththescreenandrarely(exceptinprivateorgroupscreenings)breakoutinapowerfulcollectiveresponse,muchlessapplause.Bycontrast,livetheatricalpresentationsgenerateaudienceactivitythatisbroadlysocialinnature:thecrowdarrivesatthetheaterataboutthesametime,peoplemingleandchatduringintermissions,andalldeparttogether,ofteninspiritedconversationabouttheplay.Moreover,theycommunicateduringtheplay:laughterandapplausebuilduponthemselvesandgainstrengthfromtherecognitionthatothersarelaughingandapplauding.Thefinalovationuniquetoliveperformanceinevitablyinvolvestheaudienceapplaudingitself,aswellastheperformers,forunderstandingandappreciatingthetheatricalexcellencetheyhaveallseentogether.Andplayswithpoliticalthemescanevengeneratecollectivepoliticalresponse.Inacelebratedexample,1935sWaitingforLeftywasstagedasiftheaudiencewereagroupofunionmembers;bytheplay'sendtheaudiencewasyellingStrike!Strike!inresponsetotheplay'sissues.Obviously,onlyaliveperformancecouldevokesucharesponse.
5.Inparagraph3,whichofthefollowingismentionedassupportforthestatement
200thatThisbroadcommunalresponseisneverdevelopedbytelevisiondramaA.Televisiondramaisrarelyaboutserioussocialissues.
B.Peopledonotusuallytalktoeachotherwhilewatchingtelevision.C.Televisionaudiencesvarygreatlyintheirinterestintelevisiondramas.D.Peopledonottypicallywatchtelevisioninlargegroups.
6.Accordingtoparagraph3,moviehouseaudiencesaredifferentfromaudiencesatlivetheatricalperformancesbecausemoviehouseaudiencesdonotA.enjoyhumorandjokesasmuchastheateraudiencesdoB.developbroadcommunalresponses
C.sympathizewiththecharacterstheyseedramatizedD.generallyapplaudunlesseveryoneelseisapplauding
7.WhydoestheauthormentiontheplayWaitingforLeftyA.Toillustratethepowerofthecommunalresponsetoplays
B.Toarguethatplaysaboutpoliticalsubjectshavemorepowertoevokedeep
feelingsinanaudiencethannonpoliticalplaysdo
C.Toprovideanexampleofaplaythatwasapopularsuccessbecauseitdealtwith
importantpoliticalissues
D.Tocomparethepoliticalimportanceofplaysinrecenttimeswiththepolitical
importanceofearlierplaysParagraph4
Finally,liveperformanceinevitablyhasthequalityofimmediacy.Theactionoftheplayistakingplacerightnow,asitisbeingwatched,andanythingcanhappen.Althoughinmostprofessionalproductionsthechangesthatoccurinperformancefromonenighttoanotheraresosubtlethatonlyanexpertwouldnotice,thefactisthateachnight'spresentationisunique,andeveryonepresenttheaudience,thecast,andthosebehindthescenesknowsit.Thisawarenesslendsanexcitementthatcannotbeachievedbytheatricaleventsthatarewhollyinthecan.Onereasonfortheexcitement,ofcourse,isthatinliveperformance,mistakescanhappen;thispossibilityoccasionsacertainabidingtension,perhapsevenanedgeofstagefright,whichsomepeoplesaycreatestheultimatethrillofthetheater.Butjustasdisastercancomewithoutwarning,sotoocansplendor.Onanygivennight,eachactoristryingtobetterhisorherpreviousperformance,andnooneknowswhenthiscollectiveeffortwillcoalesceintosomethingsublime.Theactors'constantstrivingtowardself-transcendencegivesthetheateravitalitythatismissingfromperformancesfixedunalterablyonvideotapeorcelluloid.Butperhapsmostappropriately,theimmediacyofliveperformanceembodiesthefundamentaluncertaintyoflife.Oneprimefunctionoftheateristoaddresstheuncertaintiesofhumanexistence,andtheveryformatofliveperformancepresentsamoment-to-momentuncertaintyrightbeforeoureyes.Ultimately,thisimmediatetheaterhelpsusdefinethequestionsandconfusionsofourlivesandletsusgrapple,inthepresent,withtheirimplications.
2018.Whichofthesentencesbelowbestexpressestheessentialinformationinthehighlightedsentenceinthepassage?Incorrectchoiceschangethemeaninginimportantwaysorleaveoutessentialinformation.
A.Althoughexpertscandetectthechangesthatoccurindifferentperformances,thechangesaretoosubtletobenoticedbyanyoneelse.
B.Althoughtheirperformancesvaryonlysubtlyfromonenighttoanother,actorsinmostprofessionalproductionswantaudiencestobelievethateveryperformanceisunique.
C.Everyoneinvolvedintheprofessionalproductionofaplayknowsthatverysmall,almostunnoticeablechangesmakeeachperformanceunique.
D.Inmostprofessionalproductions,changesareincludedfromoneperformancetoanotherthatareintendedtomakeeveryperformanceauniqueone.9.ThewordthrillinthepassageisclosestinmeaningtoA.goal
B.weaknessC.meaningD.excitement
10.ThewordvitalityinthepassageisclosestinmeaningtoA.styleB.energyC.purposeD.quality
11.Accordingtoparagraph4,onanygivennighttheresultofactors'effortstobettertheirpreviousperformancesisthattheactors
A.formlong-lastingrelationshipswiththeaudienceB.arebetterabletoovercometheirstagefright
C.createaqualitythatisnotpresentinfilmortelevisionD.aremorelikelytobeadmiredbyaudiences
12.Itcanbeinferredfromparagraph4thatoneofthereasonsfilmedperformancesarelessexcitingthanlivetheatricalperformancesisbecause
A.thereislittlechancethatamistakewilloccurinafilmedperformanceB.mostmoviesportraysituationsthataudienceshaveseenbefore
C.audiencesareinterestedinseeingfamousactorsliveratherthanonascreen
D.mostpeopleareaccustomedtogoingtothemoviesbutviewthetheaterasaspecialevent
13.Lookatthefoursquaresthatindicatewherethefollowingsentencecouldbeaddedtothepassage.
Suchsignsofanaudience'sengagementthusbecomepartofeveryperformance.
202Wherewouldthesentencebestfit?Clickonasquaretoaddthesentencetothepassage.
Thefirstoftheseistherapportexistingbetweenactorandaudience.[A]Botharebreathingthesameair;bothareinvolvedatthesametimeandinthesamespacewiththestagelifedepictedbytheplay.[B]Sometimestheirmutualfascinationisalmostpalpable;everyactor'sperformanceisaffectedbythewaytheaudienceyieldsorwithholdsitsresponses:itslaughter,sighs,applause,gasps,silences.[C]Livetheatricalperformanceisalwaysatwo-waycommunicationbetweenstageandhouse.[D]
14.Dragyourchoicestothespaceswheretheybelong.Toreviewthepassage,clickonViewText.
AnswerChoices
A.Althoughlivetheaterisunlikeeithervideoorcinema,thedifferentgenres
sometimesoverlap.
B.Whilelivetheaterisregardedbymostfilmactorsasthemostexcitingplaceto
perform,manyaretootroubledbystagefrighttoperformlive.
C.Inthetheater,thereisatwo-waycommunicationbetweenactorandaudiencethat
hasaneffectontheactor'sperformance.
D.Audiencesatlivetheatricalperformancesformaspecialconnection,sharingthe
commonexperienceofreactingtoalivetheatricalperformance.
E.Manypeoplegotothetheaterexcitedtoseeinaliveperformanceanactorthat
theyhaveneverseenbeforeexceptontelevisionorinfilms.
F.Theexcitementoflivetheatercannotbeachievedinanyothermedium,anditsimmediacyanduncertaintyhelpusdealwithlife'sfundamentaluncertainty.
EarthquakePrediction（此篇17年3月25日考到了）
Paragraph1
Accuratepredictionofearthquakesisnotcurrentlypossible,althoughintensiveresearchisproceedinginmanyareas.
Paragraph2
Twotypesofearthquakepredictionaretheoreticallypossible.Thefirsttypeislong-termforecasting,inwhichtheprobabilityofanearthquakealongaparticularsegmentofawithinacertaintimeintervaliscalculatedbystudyingseismicgapsandhistoricalrecordsofearthquakesthathaveoccurredalongthatfaultsegment.Byplottingthenumberofearthquakeswithinspecifictimeintervalsagainsttheirmagnitudes,diagramscanbeconstructedforalocalarea.Fromthisplotitispossibletodeterminetherecurrenceinterval,ortheaveragetimeintervalbetweenearthquakesofaspecificmagnitude.Predictionscanthenbemadethatanearthquakeofthat
203magnitudehasahighprobabilityofoccurrencewithinaspecifiedtimeinterval,ifthedateofthelastearthquakeisknown.
1.ThewordspecifiedinthepassageisclosestinmeaningtoA.probableB.statedC.shortD.typical
2.Accordingtoparagraph2,allofthefollowinginformationisusedintheprocessoflong-termearthquakepredictionEXCEPTtheA.analysisofseismicgaps
B.recordofpastearthquakesinthefaultareaC.dateofthelastrecordedearthquakeinthearea
D.patternofearthquakeactivityinothernearbyfaultsegments
3.Accordingtoparagraph2,long-termforecastingcanbeusedtopredictwhichofthefollowing
A.Theinfluenceofearthquakeactivityinonesegmentofthefaultareaonother
segments
B.ThefrequencywithwhichearthquakesofacertainsizewilloccurC.ThepossibledateofthenextearthquakeD.Themagnitudeofthenextearthquake
Paragraph3
Researchleadingtoshort-termforecasting,whichinvolvesashortertimeinterval,hasbeenfocusedonprecursorsobservedpriortopreviousearthquakes.Precursorsarephysicalorchemicalphenomenathatoccurinatypicalpatternbeforeanearthquake.Thesephenomenaincludechangesinthevelocityofseismicwaves,theelectricalresistanceofrocks,thefrequencyoftheusuallyminorpreliminaryearthquakes(foreshocks),thedeformationofthelandsurface,andthewaterlevelorwaterchemistryofwellsinthearea.Manyoftheseprecursorscanbeexplainedbyatheorycalledthedilatancymodel.Underthishypothesis,rocksintheprocessofstrainalongafaultshowsignificantdilationorswellingbeforerupture.Thisvolumeincreaseiscausedbytheopeningofmicrocracks,whichareminutefailurezonesinweakermineralgrainsintherockandalonggrainboundaries.Groundwaterflowsintothehighlystressedareasduringtheformationofmicrocracks.Thesechangesindensityandwatercontentaffecttheabilityoftherocktotransmitseismicwavesandconductelectricity.Therefore,seismic-wavevelocityandelectricalresistanceprogressivelychangeastheoverallrupturealongthefaultdrawsnear.Localizedchangesinland-surfaceelevationarealsorelatedtovolumechangesatdepth.AnareaofrecentupliftalongtheSanAndreasFaultnearLosAngeles,whichhasbeennamedthePalmdaleBulge,isbeingmonitoredingreatdetailasapossibleindicatorofafutureearthquake.
2044.ThewordfocusedinthepassageisclosestinmeaningtoA.dependentB.funded
C.concentratedD.published
5.Paragraph3mentionsallofthefollowingasexamplesofprecursorsEXCEPTA.changesinthespeedofseismicwavesB.changesintheavailabilityofelectricityC.changesinthefrequencyofforeshocksD.changesinlandsurfaces
6.Accordingtothedilatancymodel,whathappenstorocksshortlybeforeanearthquake
A.Theylosesignificantamountsofmoisture.B.Theyshowsignsofexpanding.
C.Theymovedownwardatgreatspeed.D.Theyincreaseintemperature.
7.Accordingtoparagraph3,thegroundwaterthatflowsintomicrocracksbeforeanearthquakecauses
A.changesinseismicwavesandelectricalactivityB.increasesinthemineralcontentofrocks
C.thedisappearanceofgrainboundariesinrocks
D.areleaseinthetensionofhighlystressedareasofrocks
8.TheauthordiscussestheSanAndreasFaultnearLosAngelesinordertoA.contrastpastandfuturepatternsofearthquakeactivityinthearea
B.giveanexampleofanareawhereundergroundearthquakeactivityisapparent
fromlandchangesabovetheground
C.explainwhyrecentearthquakepredictionshaveincreasedaccuracy
D.suggestthatsomeareasofearthquakeactivityareeasiertomonitorthanothersParagraph4
Volumechangesandgroundwatermovementmaybereflectedbychangesinwaterlevelsinwellsandalsobychangesinthechemicalcompositionofgroundwater.Radongashasbeenobservedtoincreaseinwellspriortoearthquakes.Theseincreasesareperhapsrelatedtothereleaseofradongasfromrocksduringtheformationofmicrocracks.Thepatternofseismicactivityisalsosignificantinthevicinityofafaultareawhereruptureisimminent.Thispatternconsistsofaninitialriseinthenumberofsmallevents,followedbyadeclineinforeshocksjustpriortothemajorearthquake.Thedeclinemayrepresentatemporaryincreaseinrockstrengthbeforethenewlyformedmicrocracksarefilledwithwater.
2059.Accordingtoparagraph4,whichofthefollowingoccursjustbeforeanearthquakeA.Thechemicalcontentofgroundwaterdrops.B.Therocksweakenastheyfillwithwater.C.Seismicactivitydecreases.
D.Radongascausesmicrocrackstoform.
10.ThewordimminentinthepassageisclosestinmeaningtoA.frequent
B.wellunderstoodC.knowntooccurD.abouttohappen
Paragraph 5
The precursor phenomena can be grouped into stages according to the dilatancy model. Stage I consists of a gradual stress buildup along the fault. Stages II and III are correlated with dilatancy and water influx. Stage IV is the major earthquake, and stage V is the aftermath of the event. [A] If every earthquake followed the sequence with uniform stage duration, earthquake prediction would be a simple matter. [B] Instead of following the same patterns, each earthquake is unique in terms of specific precursor behavior patterns and length of precursor stages. [C] A magnitude 6.9 North American earthquake in 1989 was preceded by a substantially smaller magnitude 5 earthquake fifteen months before the event. [D] Another foreshock of similar size occurred two months before the event. In each case, a public advisory was issued stating that those smaller earthquakes could be foreshocks to a stronger earthquake within five days. However, the fault did not cooperate, and those predictions were not successful. Continued research and study of future earthquakes will certainly lead to refinement of the dilatancy model or to a replacement model with more accurate predictive capabilities.
11. How is paragraph 5 organized
A.Thesequenceofearthquakestagesisgiven,andtheeffectofvariablestagelength
onearthquakepredictionisexplained.
B.Theearthquakestagesarenamed,andthemostimportantstageisillustratedwitha
specificearthquakeevent.
C.Thesequenceofearthquakestagesisgiven,andevidenceispresentedthatthe
intervalsbetweenstagesareroughlyequalinlength.
D.Theearthquakestagesarefirstnamed,andeachisthendescribedingreaterdetail.12.ThewordrefinementinthepassageisclosestinmeaningtoA.reconsiderationB.acceptanceC.improvementD.extension
20613.Lookatthefoursquaresthatindicatewherethefollowingsentencecouldbeaddedtothepassage.
Buttherealityofearthquakeforecastingisconsiderablymorecomplex.
Wherewouldthesentencebestfit?Clickonasquaretoaddthesentencetothepassage.
Theprecursorphenomenacanbegroupedintostagesaccordingtothedilatancymodel.StageIconsistsofagradualstressbuildupalongthefault.StagesIIandIIIarecorrelatedwithdilatancyandwaterinflux.StageIVisthemajorearthquake,andstageVistheaftermathoftheevent.[A]Ifeveryearthquakefollowedthesequencewithuniformstageduration,earthquakepredictionwouldbeasimplematter.[B]Insteadoffollowingthesamepatterns,eachearthquakeisuniqueintermsofspecificprecursorbehaviorpatternsandlengthofprecursorstages.[C]Amagnitude6.9NorthAmericanearthquakein1989wasprecededbyasubstantiallysmallermagnitude5earthquakefifteenmonthsbeforetheevent.[D]Anotherforeshockofsimilarsizeoccurredtwomonthsbeforetheevent.Ineachcase,apublicadvisorywasissuedstatingthatthosesmallerearthquakescouldbeforeshockstoastrongerearthquakewithinfivedays.However,thefaultdidnotcooperate,andthosepredictionswerenotsuccessful.Continuedresearchandstudyoffutureearthquakeswillcertainlyleadtorefinementofthedilatancymodelortoareplacementmodelwithmoreaccuratepredictivecapabilities.
14.Dragyourchoicestothespaceswheretheybelong.Toreviewthepassage,clickonViewText.AnswerChoices
Short-termforecastinghasbeenusedmorewidelythanlong-termforecastinginthepredictionofearthquakes.
B.Long-termforecastingofearthquakesusesdataonpastseismicactivitytodeterminethelikelihoodthatanearthquakewilloccurinacertainareawithinacertaintimeperiod.
C.Short-termforecastingresearchhasstudiedearthquakeprecursorssuchasvolumeincreasesinrocksandunusualmovementsinundergroundwaterthatoccurshortlybeforeanearthquaketakesplace.
D.Thedilatancymodelhasbeenusedtosuccessfullyforecastsomerecentearthquakes.
E.Attemptstoimproveforecastingbyusingfivestagesofearthquakepredictorshavebeenunsuccessfulbecauseeachearthquakehasuniqueprecursorpatternsanddurations.
F.Themagnitude6.9NorthAmericanearthquakein1989wasnotsuccessfullypredictedbecausethemanyforeshocksbeforetheeventweretoosmalltomeasure.
ThermalStratification
207热量分层：CBCDB；ADBDD；CDCABFLivePerformance
现场表演：DDBCD;BACDB;CACCDF
EarthquakePrediction（3月25日已考）地震预测：BDCCB;BABCD;ACBBCE
208
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