byHannahSperberPlanetPOWERNarrativeNonfictionPAIREDREADHeliosandPhaetonASTRATEGIES&SKILLSPhotographyCredit:RobertGlusic/CORBIS**Thetotalwordcountisbasedonwordsintherunningtextandheadingsonly.Numeralsandwordsincaptions,labels,diagrams,charts,andsidebarsarenotincluded.WordCount:1,763**ComprehensionStrategy:AskandAnswerQuestionsSkill:MainIdeaandKeyDetailsVocabularyStrategyLatinandGreekPrefixesVocabularycoincidence,consequences,consume,converted,efficient,incredible,installed,renewableContentStandardsScienceEarthScienceCopyright©TheMcGraw-HillCompanies,Inc.Allrightsreserved.Nopartofthispublicationmaybereproducedordistributedinanyformorbyanymeans,orstoredinadatabaseorretrievalsystem,withoutthepriorwrittenconsentofTheMcGraw-HillCompanies,Inc.,including,butnotlimitedto,networkstorageortransmission,orbroadcastfordistancelearning.Sendallinquiriesto:McGraw-HillEducationTwoPennPlazaNewYork,NewYork10121ISBN:978-0-02-118922-9MHID:0-02-118922-6PrintedintheUnitedStates.123456789QLM151413121110byHannahSperberPlanetPOWERPAIREDREADIntroduction.................................2Chapter1ThePowerofWater.........................4Chapter2HeatfromtheInside.........................7Chapter3ThePoweroftheSun......................10Conclusion..................................14RespondtoReading........................15HeliosandPhaeton...............16Glossary/Index..............................19FocusonScience...................20EssentialQuestionHowhaveourenergyresourceschangedovertheyears?Thinkstock/MasterfileIntroductionBurningcoalgeneratesabout50percentoftheelectricityintheUnitedStates.2Energyisincredible.WeuseittolightandheatourhomesandtopowerourTVsandcomputers.Somuchofwhatweuseanddodependsonenergy!PeoplehavebeenusingEarth’senergysinceancienttimes.Aslongagoas3500BCE.,peopleusedthewindtomovesailboats.Theyusedthesuntoheattheirhomes,andwaterwheelsandwindmillstogrindgraintomakeflour.Today,peopleusefossilfuelssuchasoil,gas,orcoal.Fossilfuelswereformedfromplantsandanimalsthatlivedmillionsof...
