下学期unit1project高一英语课件
日期：2010-01-02 01:04
inordertokeepwatermovingpasttheirgillslitsbutthisisnottrueofallspeciesNursesharks，Unit1ProjectProducingaTVshowSharkattacksSharkSpeciesWhalesharkBaskingsharkGreatwhiteTigersharkBluesharkWhatareSharks?SharksarefishthathavebeenaroundsincethedinosaursMalesarecalled“Bulls”Femalesarecalled"Cows"BabySharksarecalled"Pups“Moreinformation(new-brunswicknet/newbrunswick/shark/typeshtml)OthersharkfactsSharkshavefivetosevengillslitsManysharksmustkeepmovinginordertobreathethatis，allsharksmustswiminordertoavoidsinkingtowardtheoceanfloorThesharkhassensesspeciallyadaptedfortheanimalslifeunderwaterSmellisasharksmostacutesenseApproximately70percentofthesharksbrainisusedforolfactory(smelling)?functionsExperimentshaveshownthatsharkscandetectpreysolelybysmell，andthehungriertheshark，canliestillandfantheirgillstobringoxygen-richwateracrosstheslitsBecausetheylackaswimbladder，forexample，thelessstimulantneededtoelicitareactionSharksaresensitivetolightandcandetectcerta，
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