byEllenFullerbyEllenFullerCover,©CarstenPeter/NationalGeographic/GettyImages;p.4–5,©F.Lukasseck/Masterfile;p.6-7,©JeffHunter/TheImageBank/GettyImages;p.8-9,©AdamJones/VisualsUnlimited/GettyImages;p.10–11,©COLINMONTEATH/HEDGEHOGHOUSE/MindenPictures;p.12,©BerndKohlhas/zefa/Corbis;p.13,©GeorgeSteinmetz/Corbis;p.14,©RobertHolmes/Corbis.Cartography,p.3,JoeLeMonnierCopyright©byHarcourt,Inc.Allrightsreserved.Nopartofthispublicationmaybereproducedortransmittedinanyformorbyanymeans,electronicormechanical,includingphotocopy,recording,oranyinformationstorageandretrievalsystem,withoutpermissioninwritingfromthepublisher.RequestsforpermissiontomakecopiesofanypartoftheworkshouldbeaddressedtoSchoolPermissionsandCopyrights,Harcourt,Inc.,6277SeaHarborDrive,Orlando,Florida32887-6777.Fax:407-345-2418.HARCOURTandtheHarcourtLogoaretrademarksofHarcourt,Inc.,registeredintheUnitedStatesofAmericaand/orotherjurisdictions.PrintedinChinaISBN10:0-15-350789-6ISBN13:978-0-15-350789-2OrderingOptionsISBN10:0-15-350601-6(Grade4On-LevelCollection)ISBN13:978-0-15-350601-7(Grade4On-LevelCollection)ISBN10:0-15-357926-9(packageof5)ISBN13:978-0-15-357926-4(packageof5)Ifyouhavereceivedthesematerialsasexaminationcopiesfreeofcharge,HarcourtSchoolPublishersretainstitletothematerialsandtheymaynotberesold.Resaleofexaminationcopiesisstrictlyprohibitedandisillegal.Possessionofthispublicationinprintformatdoesnotentitleuserstoconvertthispublication,oranyportionofit,intoelectronicformat.1234567891098512111009080706HikingisverypopularattheGuadalupe-NipomoDunesNationalWildlifeRefuge.ThisbeautifulareaisontheCaliforniacoast.ItisaboutmidwaybetweenthecitiesofLosAngelesandSanFrancisco.Hikerscometotheareatoobserveitsmanybeautifulsanddunes.Likemountains,dunesarehillylandformsthatriseupfromtheEarth’ssurface.Dunesandmountains,however,forminverydifferentways.ThemovementsoftheEarth’scrustformsomemountains.Eruptingvolcanoesformothermountains.Dunesareformedmuchmoresimplythanmountains.3Mountainsoftentakemillionsofyea...
