byAlyssaLaurenCover,©PhotoResearchers;p.3,©PalHermansen/Stone/GettyImages;p.4,©DavidR.Frazier/PhotoResearchers,Inc.;p.5,©CHRISTIANDARKIN/SCIENCEPHOTOLIBRARY/PhotoResearchers;p.6–7,©ArchivoIconografico,S.A./CORBIS;p.8,p.9,p.10,©APPhoto/FrancisLatreille/NovaProductions;p.11,©Novosti/PhotoResearchers,Inc.;p.12,(tl)©PhotoDisc,(tr)©Corbis,(b)©JonathanBlair/CORBIS;p.13,(l)©APPhoto/LaCrosseTribune,DickRiniker,(r)©DaveKing/DorlingKindersley/GETTYIMAGES;p.14,©GianniDagliOrti/CORBIS.Copyright©byHarcourt,Inc.Allrightsreserved.Nopartofthispublicationmaybereproducedortransmittedinanyformorbyanymeans,electronicormechanical,includingphotocopy,recording,oranyinformationstorageandretrievalsystem,withoutpermissioninwritingfromthepublisher.RequestsforpermissiontomakecopiesofanypartoftheworkshouldbeaddressedtoSchoolPermissionsandCopyrights,Harcourt,Inc.,6277SeaHarborDrive,Orlando,Florida32887-6777.Fax:407-345-2418.HARCOURTandtheHarcourtLogoaretrademarksofHarcourt,Inc.,registeredintheUnitedStatesofAmericaand/orotherjurisdictions.PrintedinChinaISBN10:0-15-350987-2ISBN13:978-0-15-350987-2OrderingOptionsISBN10:0-15-350601-6(Grade4On-LevelCollection)ISBN13:978-0-15-350601-7(Grade4On-LevelCollection)ISBN10:0-15-357940-4(packageof5)ISBN13:978-0-15-357940-0(packageof5)Ifyouhavereceivedthesematerialsasexaminationcopiesfreeofcharge,HarcourtSchoolPublishersretainstitletothematerialsandtheymaynotberesold.Resaleofexaminationcopiesisstrictlyprohibitedandisillegal.Possessionofthispublicationinprintformatdoesnotentitleuserstoconvertthispublication,oranyportionofit,intoelectronicformat.1234567891098512111009080706byAlyssaLaurenAbout40,000yearsago,inacoldlandnowknownasSiberia,large,woollycreaturesroamedtheEarth.SiberiaisintheeasternpartofthecountryofRussia.Thesecreatures,nowknownasmammoths,werethedistantcousinsoftoday’selephants.Mammothsbegantodieoutabout10,000yearsago.In1799,ahuntersawsomehugebonesstickingoutofthecold,frozenlandofSiberia.Somethoughtthebonesbelongedtoeerie,hugebeastst...
