英语四级快速阅读专项练习(含答案解析)-文档

18/20英语四级快速阅读专项练习(含答案解析)（一）SkimmingandScanningDirections:Inthispart,youwillhave15minutestogooverthepassagequicklyandanswerthequestionsonAnswerSheet1.Forquestions1-7,choosethebestanswerfromthefourchoicesmarked[A],[B],[C]and[D].Forquestion8-10,completethesentenceswiththeinformationgiveninthepassage.AnimalsontheMoveItlookedlikeascenefrom“Jaws”butwithoutthedramaticmusic.Ahugesharkwasslowlyswimmingthroughthewater,itstailswingingbackandforthlikethependulumofaclock.Suddenlysensitivenerveendingintheshark’sskinpickedupvibrationsofastrugglingfish.Thesharkwasimmediatelytransformedintoadeadly,efficientmachineofdeath.Withmusclestaut,thesharkknifedthroughthewateratarapidspeed.Inaflashthesharkcaughtitsvictim,alargefish,initspowerfuljaws.Then,jerkingitsheadbackandforth,thesharktorehugechunksoffleshfromitsvictimandswallowedthem.Soontheactionwasover.MovingtoSurviveInpursuingitsprey,thesharkdemonstratedinadramaticwaytheimportantroleofmovement,orlocomotion,inanimals.Liketheshark,mostanimalsusemovementtofindfood.Theyalsouselocomotiontoescapeenemies,findamate,andexplorenewterritories.Themethodsoflocomotionincludecrawling,hopping,slithering,flying,swimming,orwalking.Humanshavetheaddedadvantageofusingtheirvariousinventionstomoveaboutinjustaboutanykindofenvironment.Automobiles,rockets,andsubmarinestransporthumansfromdeepoceanstoasfarawayasthemoon.However,forotheranimalsmovementcameaboutnaturallythroughmillionsofyearsofevolution.Oneofthemostsuccessfulexamplesofanimallocomotionisthatoftheshark.Itsabilitytoquicklyzeroinonitspreyhasalwaysimpressedscientists.ButittookadetailedstudybyDukeUniversitymarinebiologistsS.A.Wainwright,F.Vosburgh,andJ.H.Hebranktofindouthowthesharksdidit.IntheirstudythescientistsobservedsharksswimminginatankatMarinelandinSaintAugustine,Fla.Moviesweretakenofthesharks’movementsandanalyzed.Studieswerealsomadeofsharkskinandmuscle.SkinIstheKeyThebiologistsdiscoveredthattheskinofthesharkisthekeytotheanimal’shighefficiencyinswimmingthroughthewater.Theskincontainsmanyfibersthatcrisscrossliketheinsideofabeltedradialtire.Thefibersarecalledcollagenfibers.Thesefiberscaneitherstoreorreleaselargeamountsofenergydependingonwhetherthefibersarerelaxedortaut.Whenthefibersarestretched,energyisstoredinthemthewayenergyisstoredinthestringofabowwhenpulledtight.Whentheenergyisreleased,thefibersbecomerelaxed.TheDukeUniversitybiologistshavefoundthatthegreateststretchingoccurswherethesharkbendsitsbodywhileswimming.Duringthebody’sbackandforthmotion,fibersalongtheoutsidepartofthebendingbodystretchgreatly.Muchpotentialenergyisstoredinthefibers.Thisenergyisreleasedwhentheshark’sbodysnapsbacktheotherway.Asenergyisalternatelystoredandreleasedonbothsidesoftheanimal’sbody,thetailwhipsstronglybackandforth.Thiswhip-likeactionpropelstheanimalthroughthewaterlikealivingbullet.SourceofEnergyWhatcausesthefiberstostoresomuchenergy?InfindingtheanswertheDukeUniversityscientistslearnedthattheshark’ssimilaritytoabeltedradialtiredoesn’tstopwiththeskin.Justasaradialtireisinflatedbypressure,so,too,istheareajustundertheshark’scollagen“radials”.Insteadofairpressure,however,thepressureinthesharkmaybeduetotheforceofthebloodpressingonthecollagenfibers.Whenthesharkswimsslowly,thepressureonthefibersisrelativelylow.Thefibersaremorerelaxed,andthesharkisabletobenditsbodyatsharpangles.Theanimalswimsthiswaywhenlookingaroundforfoodorjustswimming.However,whenthesharkdetectsanimportantfoodsource,somefantasticinvoluntarychangestakeplace.Thepressureinsidetheanimalmayincreaseby10times.Thispressurechangegreatlystretchesthefibers,enablingmuchenergytobestored.Thisenergyisthentransferredtothetail,andthesharkisoff.Therestofthestoryispredictable.DolphinHasSpeedRecordAnotherfastmarineanimalisthedolphin.Thisseagoingmammalhasbeenclockedatspeedsof32kilometers(20miles)anhour.Biologistsstudyingthedolphinhavediscoveredthat,liketheshark,theanimal’sefficientlocomotioncanbetracedtoitsskin.Adolphin’sskinismadeupinsuchawaythatitoffersverylittleresistancetothewaterflowingoverit.Normallywhenafishorotherobjectmovesslowlythroughthewater,thewaterflowssmoothlypastthebody.Thissmoothflowisknownaslaminarflow.However,atfasterspeedsthewaterbecomesmoreturbulentalongthemovingfish.Thisturbulencemusesfrictionandslowsthefishdown.Inadolphintheskinissoflexiblethatitbendsandyieldstothewavinessofthewater.Thewaves,ineffect,becometuckedintotheskin’sfolds.Thisallowstherestofthewatertomovesmoothlybyinalaminarflow.Whereotheranimalswouldbeslowedbyturbulentwateratrapidspeeds,thedolphincanracethroughthewateratrecordbreakingspeeds.OtherAnimalsLessEfficientNotallanimalsmoveasefficientlyassharksanddolphins.Perhapsthegreatestloserinlocomotionefficiencyistheslug.Theslug,whichlookslikeasnailwithoutashell,laysdownaslimytrailoverwhichitcrawls.Itusessomuchenergyproducingtheslimymucusandcrawlingoveritthatamousetravelingthesamedistanceusesonlyonetwelfthasmuchenergy.Scientistssaythatbecauseoftheslug’sinefficientuseofenergy,itslifestylemustberestricted.Thatis,theanimalsareforcedtoconfinethemselvestosmallareasforobtainingfoodandfindingproperlivingconditions.Havehumanseverbeenfacedwiththiskindofproblem?1.Accordingtothepassage,asharkcanusemovementtodosomethingexcept____________.[A]tofindfood[B]toavoidbeingchasedbyitsenemies[C]tofindanewplacetolive[D]toshowitsbraveness2.Examplesofautomobiles,rocketsandsubmarinesareusedtoshowthat_______________.[A]humansarethemostcleverlivingcreaturesintheworld[B]humaninventionsenableustotravelinalmostanykindofenvironment[C]humansareverysuccessfulininventingtransportationtools[D]humanscan’tmovelikeotheranimalsinanycircumstances3.Whatisthekeytotheshark’sswiftlocomotioninwater?[A]Theskin.[B]Thetail.[C]Themuscle.[D]Thejaw.4.AccordingtotheDukeUniversityscientists,whendoesthesharkstretchitscollagenfiberstothegreatestextent?[A]Whenmovingitstailrapidly.[B]Whenfindingitspreys.[C]Whenstayingwithoutanymovement.[D]Whenbendingitsbodyinswimming.5.Whyistheareajustundertheshark’scollagenfiberssimilartoabeltedradialtire?[A]Becauseitisalsofullofbloodpressure.[B]Becauseitisalsofilledofairpressure.[C]Becauseitisalsoinflatedbypressure.[D]Becauseitalsocanbeusedagainandagain.6.Alaminarflowisformedwhenafishswims________________.[A]slowlythroughthewater[B]rapidlythroughthewater[C]againstthecurrent[D]atthefastestspeedinwater7.Consumingtheequalamountofenergyasaslugdoes,amousecantravel_________aslongasaslug.[A]onetwelfthtimes[B]thesame[C]12times[D]1.2times8.Asharkfindsitspreyby________________.9.Accordingtothepassage,_______________canbecomparedtothestringofabowforbothofthemstoreenergywhenstretched.10.Whenthesharkdetectsanimportantfoodsource,_______________________takeplace.（二）Directions:Inthispart,youwillhave15minutestogooverthepassagequicklyandanswerthequestionsonAnswerSheet1.Forquestions1-7,choosethebestanswerfromthefourchoicesmarkedEAI,IB3,ICIandIDa.Forquestions8-10,completethesentenceswiththeinformationgiveninthepassage.AboutStoryReaderParentsdearlyhopetheirchildrenlearntoreadwell.Theyalsohopetheirchildrenlearntoreadquicklyandeasily,sothatthey’rereadyforthedemandsputonthembyschoolandtheworld.Kidswanttolearnhowtoread,buttheyalsocraveentertainment,whetherit’squietandpassiveordynamicandinteractive.TheaimsoftheStoryReaderlineofelectronicbooksaretoentertainchildrenandtointroducethemtotheprocessoflearninghowtoreadinagentleandenjoyableway.Inthisarticle,we’llshowyouhowStoryReaderworksandifitaccomplishesthatgoal.StoryReaderisacompact,roughly12-inch-by-12-inchplasticcase(withacarryinghandle)thatopenstorevealanactualbookthatfitssnuglyintotheReaderitself.StoryReader’scorefeatureisthatit"reads"thebookaloudtoachildashefollowsalong.ThechildturnsthepageswhenpromptedbytheStoryReaderorathisownpace.Bookshavebothtextandillustrations.Theelectronicbookrespondstothechild’swishes.TheStoryReaderspeaksthetextforthecurrentpage.Ifthechildturnsbackafewpages,theReaderrecognizesthatpageandreadsitagain.Kidsreactwelltothisinteractivitybecauseitinstillsasenseofcuntroloverthestory.ThereareThreeStoryReaderProductsThebasicStoryReader,introducedin2003,isasdescribedaboveandisintendedforkidsthreeyearsofageandolder.Eachbookhasasmallcompanioncartridgethatslidesintoaportonthecaseandcontainstheaudioencodedintoitsmemoryforthestory.Thedevicehasavolumecontrolbutnoon/offswitch--adeliberatechoicesokidscansimplyopenitupandbeginreading.IttakesfourAAAbatteries(oroperatesonhouseholdcurrentwithanoptionaladaptor)andretailsforaround$20.Findoutmoreinformationaboutthemorethan60titlesattheStoryReaderwebsite.Earlyin2006,PublicationsInternational,Ltd.--StoryReader’spublisher--introducedMyFirstStoryReader,designedfornewbornstokidsuptoagethree.Aswiththeoriginal,anarratorreadsthestoryaloud,thistimefroma12bookmadefromaheavierpaperstockthatincludessoundeffectsandmusictoenliventheexperience.MyFirstStoryReaderfeaturestwoplaymodes,onewithnarration,theotherthatasksquestionsabouttheimagesoneachpage.Thechildcanpressanyofthreebuttonstoanswerbasicquestionsaboutshapesandcolors.ThelasttwopagesofeachMyFirstStoryReaderbookfeaturesasing-alongrhymingmelody.MyFirstStoryReaderretailsforabout$20.Latein2006,PublicationsInternationalintroducedavideoversionofStoryReadercalledStoryReaderVideoPlusforkidsuptotheageofseven.Retailingforabout$35,itcombinesastand-aloneStoryReaderwithan"AnimatedStoryMode"thatplaysthroughyourtelevisionandincludesa"LearningGameMode".TheAnimatedStoryModeworksjustasitsounds--whenyouconnectittoyourtelevisionthroughcolor-codedcables,thestoryappearsonscreenandchangesasyourchildturnsthepages.KidsgettotheLearningGameModebyturningtothelastpageofthebook.There,theycanchoosefromfiveeducationalgames.Whileitdependsonthestory,generallytherearepatterngames,memorygames,andplatformgames.SimilartoNintendogameslikeSuperMarioBrothers,inaplatformgamethechildusestheincludedcontrollertoguidehimthroughtheenvironmentandconquerobstacles.StoryReaderVideoPlusisn’tavideogame,technically,andPublicationsInternationalbillstheStoryReaderlinemoreaselectronicbooksthantoys.Thisreassuresmanyparents,andit’swhyStoryReaderissoldinbookstoresandinthebooksectionofmajorretailers.WhatabouttheEducationalUnderpinningsofStoryReader?StudiesshowanalarmingdeclineinreadingratesamongallagegroupsinAmerica,especiallyamongtheyoung.Childrenarebombardedonadailybasiswithmultipleformsofentertainmentthatcompetewithtraditionallearning.Kidsnaturallyemulatetheadultsintheirlives,andseeingtheirparentsandotherfamilymembersenjoyreadingisapowerfulmotivator.EstablishingandkeepingaRead-At-HomeNighthelpsfamiliesspendtimetogetherandhelpsformlifelongreadinghabitsinchildren.Here’showyoudoit:·Setasideonenightaweekinyourhouseholdandcallit"Read-At-HomeHour"--oranythingyouprefer.Establishatimeallotmentthatworksforyourfamily,forexample,30minutesoranhour.·MinimizeinterruptionsfromtheTV,computer,andvideogames--andturnonthetelephoneansweringmachine.·Chooseonebookfortheentirefamilytoreadaloudtogether,orencourageindividualfamilymemberstochoosetheirownbookstoreadquietly.Electronicbookscanworkinthiscontext,aswell.·Finally,sitdown,relax,andread.1.TheaimsoftheStoryReaderlineofelectronicbooksare__[A]toentertainandteachchildren[B]toplaywiththechild[C]toeasetheparents’burden[D]toeasetheteachers’burden2.StoryReader’skeycharacteristicisthat__[A]it"reads"thebookwhichthechildlikes[B]it"reads"thebookwhilethechildplays[C]it"reads"thebookwhilethechildfollowsalong[D]it"reads"thebookwhiletheparentworks3.Children__aresuitableusersofthebasicStoryReader.[A]uptosixmonthsold[B]uptoageone[C]uptoagetwo[D]uptoagethree4.ThebasicStoryReaderforsaleisabout__[A]12dollars[B]20dollars[C]35dollars[D]60dollars5.MyFirstStoryReaderischaracteristicwith[A]twoplaymodes[B]threeplaymodes[C]fourplaymodes[D]fiveplaymodes6.StoryReaderVideoPlusisavideoversionofStoryReaderdesignedfor__[A]newbornstokidsuptoagethree[B]newbornstokidsuptoageseven[C]childrenuptotheageoffive[D]childrenuptotheageofseven7.HowmanygamescanchildrenchoosefromtheAnimatedStoryMode?[A]four[B]five[C]six[D]seven8.IftheStoryReaderspeaksthetextforthecurrentpage,butthechildtumsbackafewpages,itwill__________9.Latein2006,wecaninferthattherewereStoryReaderproducts___________.10.LikeSuperMarioBrothers,childreninaplatformgameusetheincludedcontrollersto__________（三）

ReadingComprehension(SkimmingandScanning)(15minutes)Directions:Inthispart,youwillhave15minutestogooverthepassagequicklyandanswerthequestionsonAnswerSheet1.Forquestions1-7,choosethebestanswerfromthefourchoicesmarked[A],[B],[C]and[D].Forquestions8-10,completethesentenceswiththeinformationgiveninthepassage.TheRightAmountofEnergyWeallenjoybeingaroundpeoplewithenergy.Theyinspireus.Theyarestimulating,fun,anduplifting.Anenergeticpersonhaspassioninhisvoice,abounceinhisstep,andasmileonhisface.Energymakesapersonlikable,andlikabilityisakeyingredientinpersuasivecommunications.Manybusinessprofessionalsunderestimatetheenergylevelrequiredtogenerateenthusiasmamongtheirlisteners.Butelectrifyingspeakersbringit.Theyhaveanenergythatisseverallevelshigherthanthepeopletheyareattemptingtoinfluence.MostbusinessprofessionalscoulduseanenergyboostforpublicspeakingsituationssuchasWebinars,podcasts,staffmeetings,conferencecalls,andtelevisionandradiointerviews.Eachoftheseopportunitiesrequiresahigherlevelofenergythanwouldnormallybeappropriateifyouwerejustchattingtosomeoneinthehallway.Buthowdoyouprojecttherightlevelofvigorwithoutseemingoverthetop?Byweighingyourselfonanenergyscale.Andonthisscale,moreisbetter.TheEnergyScaleRecentlyIhelpedanexecutiveprepareforhisfirstmajorpresentationinhisnewrole."Tellmewhereyourenergyisrightnowonascaleofonetoten,"Iasked."OnebeingfastasleepandtenbeingJimCrameronMadMoney.Youknow,theguywho’syellingandgesturingwildlyonhisCNBCshow.Whereareyounow?""Athree,"thespeakerreplied."OK,whatwoulditfeelliketobeaseven,eightornine?Giveitatry,"Isuggested.Ifthey’rebeinghonest,mostpresentersplacethemselvesatathreetosixontheenergyscale.Thatmeansthereisplentyofroomtoboostyourenergywhilenotappearingtoozany.Butkeepinmind,onceyouhitatenorhigher,youcouldbethenextYouTube(GOOG)hit--whichisnotnecessarilyyourtopobjective!Hereareseveralsurefirestrategiestoboostyourenergypresence.1.Practiceleavingyourcomfortzone.Recordseveralminutesofyourpresentationasyouwouldnormallydeliverit:Playitback,preferablywithsomeoneelsewatchingandlisteningaswell.Askyourselfandtheobserver,whereamIontheenergyscale?Nowtryitagain.Thistime,breakoutofyourcomfortzone.Hamitup.Raiseyourvoice.Usebiggestures.Putabigsmileonyourface.Gettoapointwhereyouwouldfeelslightlyawkwardanduncomfortable.Nowwatchit.Mostlikelyyourenergylevelwillbefarmoreengagingandstillremainappropriatefurthesituation.2.Smileandhavefun.WhydomostpeopleseemtoenjoyVirginentrepreneurRichardBranson?Becausetheguyhasfunanditshows.Healwayshasawarm,engagingsmileonhisface.Ofcourse,youcanarguethatit’seasytowalkaroundwithasmilewhenyou’reworth$4billion!Butseriously,smile.Itwon’thurtanditwillmakeyoumorelikable.Mostbusinessprofessionalsdon’tsmileasmuchastheyshouldduringpresentations.I’mhelpingsomeexecutivesprepareforCES,thebigConsumerElectronicsShowinJanuarywheretheywillannouncenewproducts.Theygetsocaughtupintheslidesandwhatthey’regoingtosay(astheyshouldduringpreparation),theyforgetthatnewproductsbringjoytotheirconsumers.Inmostcases--withtheexceptionofbadnews,ofcourse--thefirstandlastthingyousaytoyourselfbeforelaunchingintoyourpresentationshouldbe,"Have3.Getyourbodymoving.Manypeopleareuncomfortableusingexpansivehandgestures.Don’tbe.IspoketoDavidMcNeillattheUniversityofChicago,whoisknownforhisresearchintogestureandspeech.Hesaysthatclear,confidentspeakersusehandgesturesandthatthegesturesleaveapositiveimpressiononlisteners.Hewentontosaythatusinggestureswillhelpyouspeakbetterbecauseformostofusittakeseffortnottousegestures.Don’tbeafraidofusingyourhands.AOL’s(TWX)Tisoneofmyfavoritevideosearchengines.Iuseittoretrieveclipsofbusinessspeakerstostudytheirbodylanguage.Symantec’s(SYMC)JohnThompson,Oracle’s(ORCL)LarryEllison,Cisco’s(CSCO)JohnChambers,andeBay’s(EBAY)MegWhitmanareexcellentexamplesofpeoplewithconfident,energeticbodylanguage.4.StudyTVandradiopersonalities.Starsoftelevisionandradiowhoscorehighonthelikabilityscalehavehigh-energypersonalities.IhadaconversationwithSuzeOrmanoverthephoneacoupleofyearsagoandrememberittothisday.Herenergycomesrightthroughthespeaker.WhatyouseeonherCNBCshowiswhatyougetbehindthescenes.Highenergy.TheotherdayIwatchedFoodNetwork(SSP)starRachaelRaysignbooksatamallwhereIhappenedtobeshopping.Sometimescriticspokefunather"perky"personalityandphraseslike"yum-o,"butthefactisshehasenergyandmillionsofviewersenjoyit.Thenetworkmorning-showhostsaretypicallychosenfortheirenergeticpersonalities.Today’sMattLaueronNBC(GE)andTheEarlyShow’sJulieChenonCBS(CBS)areexcellentexamples,buttherearemanyothersonmorningtelevision.Remember,maintaininganenergeticpresenceisverydifficulttodounlessyou’reinvolvedwithsomethingyouenjoy.Ifyouaretrulypassionateaboutyourcompany,product,orservice,thenshowit.Speakwithenergyandvitality.Yourlistenerswillloveyouforit.l.Fromthefirstparagraph,whatisakeypointinpersuasivecommunication?[A]Stimulation.[B]Uplitting.[C]Fun.[D]Likability.2.Haveanenergyseverallevelshigherthanthepeopletheyareattemptingtoinfluence.[A]Electrifyingspeakers[B]Businessprofessionals[C]Und.vnamicpersons[D]Listeners3.Howdopeopleshowtherightlevelofenergywithoutseemingoverthetop’?[A]Byunderestimatingtheenergylevel.[B]Byundervaluingtheenergylevel.[C]Byestimatinganenergyscale.[D]Byusingalowerlevelofenergy.4.Thescaleoftheenergyis[A]seven,eightornine[B]tenorhigher[C]threetosix[D]onetoten5.Whatdoestheexamplemeaninthethirdparagraph?[A]Thereislittleroomtoboostyourenergywhilenotappeanngtoozany.[B]Thereisalittleroomtoboostyourenergywhilenotappearingtoozany.[C]Thereismuchroomtoboostyourenergywhilenotappearingtoozany.[D]Thereisnoroomtoboostyourenergywhilenotappearingtoozany.6.WhyisVirginentrepreneurRichardBransonpopular?[A]Becausehehasfunanditshows.[B]Becausehedoesn’tsmileasmuchasheshouldduringpresentations.[C]Becauseheisveryhumorous.[D]Becauseheisfamous.7.DavidMcNeillsaysthatconfidentspeakersuse__[A]handgestures[B]speech[C]smile[D]expression8.IuseAOL’s(TWX)Ttoretrieveclipsofbusinessspeakersto__________9.Starsoftelevisionandradiowhoscorehighonthelikabilityscalehave__________10.Maintaininganenergeticpresenceisverydifficulttodounless__________（四）TheEarthPowerandLightComparedtotherestoftheuniverse,theEarthisverysmall.OurplanetandsevenothersorbittheSun,whichisonlyoneofabout200billionstarsinourgalaxy.Ourgalaxy,theMilkyWay,ispartoftheuniverse,whichincludesmillionsofothergalaxiesandtheirstarsandplanets.Bycomparison,theEarthismicroscopic.Comparedtoaperson,ontheotherhand,theEarthisenormous.Ithasadiameterof7,926miles(12,756kilometers)attheequator,andithasamassofabout6x1024kilograms.TheEarthorbitstheSunataspeedofabout66,638milesperhour(29.79kilometerspersecond).Don’tdwellonthosenumberstoolong,though;toalotofpeople,theEarthisinconceivably,mind-bogglinglybig.Andit’sjustafractionofthesizeoftheSun.FromourperspectiveonEarth,theSunlooksverysmall.Thisisbecauseit’sabout93millionmilesawayfromus.TheSun’sdiameteratitsequatorisabout100timesbiggerthanEarth’s,andaboutamillionEarthscouldfitinsidetheSun.TheSunisinconceivably,mind-bogglinglybigger.ButwithouttheSun,theEarthcouldnotexist.Inasense,theEarthisagiantmachine,fullofmovingpartsandcomplexsystems.Allthosesystemsneedpower,andthatpowercomesfromtheSun.TheSunisanenormousnuclearpowersource--throughcomplexreactions,ittransformshydrogenintohelium,releasinglightandheat.Becauseofthesereactions,everysquaremeterofourplanet’ssurfacegetsabout342WattsofenergyfromtheSuneveryyear.Thisisabout1.7~1017Wattstotal,orasmuchas1.7billionlargepowerplantscouldgenerate.YoucanlearnabouthowtheSuncreatesenergyinHowtheSunWorks.WhenthisenergyreachestheEarth,itprovidespowerforavarietyofreactions,cyclesandsystems.Itdrivesthecirculationoftheatmosphereandtheoceans.Itmakesfoodforplants,whichmanypeopleandanimalseat.LifeonEarthcouldnotexistwithouttheSun,andtheplanetitselfwouldnothavedevelopedwithoutit.Toacasualobserver,theSun’smostvisiblecontributionstolifearelight,heatandweather.NightandDaySomeoftheSun’sbiggestimpactsonourplanetarealsoitsmostobvious.AstheEarthspinsonitsaxis,partsoftheplanetareintheSunwhileothersareintheshade.Inotherwords,theSunappearstoriseandset.Thepartsoftheworldthatareindaylightgetwarmerwhilethepartsthataredarkgraduallylosetheheattheyabsorbedduringtheday.YoucangetasenseofhowmuchtheSunaffectstheEarth’stemperaturebystandingoutsideonapartlycloudyday.WhentheSunisbehindacloud,youfeelnoticeablycoolerthanwhenitisn’t.ThesurfaceofourplanetabsorbsthisheatfromtheSunandemitsitthesamewaythatpavementcontinuestogiveoffheatinthesummeraftertheSungoesdown.Ouratmospheredoesthesamething-itabsorbstheheatthatthegroundemitsandsendssomeofitbacktotheEarth.TheEarth’srelationshipwiththeSunalsocreatesseasons.TheEarth’saxistipsalittle-about23.5degrees.OnehemispherepointstowardtheSunastheotherpointsaway.ThehemispherethatpointstowardtheSuniswarmerandgetsmorelight--it’ssummerthere,andintheotherhemisphereit’swinter.Thiseffectislessdramaticneartheequatorthanatthepoles,sincetheequatorreceivesaboutthesameamountofsunlightallyear.Thepoles,ontheotherhand,receivenosunlightatallduringtheirwintermonths,whichispartofthereasonwhythey’refrozen.Mostpeoplearesousedtothedifferencesbetweennightandday(orsummerandwinter)thattheytakethemforgranted.Butthesechangesinlightandtemperaturehaveanenormousimpactonothersystemsonourplanet.Oneisthecirculationofairthroughouratmosphere.Forexample:TheSunshinesbrightlyovertheequator.TheairgetsverywarmbecausetheequatorfacestheSundirectlyandbecausetheozonelayeristhinnerthere.Astheairwarms,itbeginstorise,creatingalowpressuresystem.Thehigheritrises,themoretheaircools.Watercondensesastheaircools,creatingcloudsandrainfall.Theairdriesoutastherainfalls.Theresultiswarm,dryair,relativelyhighinouratmosphere.Becauseofthelowerairpressure,airrushestowardtheequatorfromthenorthandsouth.Asitwarms,itrises,pushingthedryairawaytothenorthandthesouth.Thedryairsinksasitcools,creatinghigh-pressureareasanddesertstothenorthandsouthoftheequator.ThisisjustonepieceofhowtheSuncirculatesairaroundtheworld--oceancurrents,weatherpatternsandotherfactorsalsoplayapart.Butingeneral,airmovesfromhigh-pressuretolow-pressureareas,muchthewaythathigh-pressureairrushesfromthemouthofaninflatedballoonwhenyouletgo.Heatalsogenerallymovesfromthewarmerequatortothecoolerpoles.Imagineawarmdrinksittingonyourdesk--theair