Thesunissettingonasummernight．Attheentranceofadeep，darkcave，afewbatsflyout．Withinafewminutes，millionsandmillionsofbatsarepouringoutofthecave．Soundslikeascaryhorrormovie？Believeitornot，thissc

　　Thesunissettingonasummernight．Attheentranceofadeep，darkcave，afewbats flyout．Withinafewminutes，millionsandmillionsofbatsarepouringoutofthecave．

　　Soundslikeascaryhorrormovie？Believeitornot，thisscenetakesplaceallsummer long，atBrackenCaveinTexas，where20millionbatscomeouttofeedoninsectsevery night．"Itismagical，"saysJimKennedyofBatConservationInternationalinTexas．"Itis oneofthemostimpressiveanimalmovementsontheplanet．"

　　EveryMarchorApril，Mexicanfree-tailedbatsmigrateupto1，600kilometersfrom theirwinterhomeinMexicototheirAmericanhomeinTexas，wheretheyraisetheir young．Soonaftertheyarrive，eachmothergivesbirthtoonebaby．Asmanyas500，baby batscrowdinto30cubiccentimetersofspace．andallthosebodiescreatenicewarmtem-peraturestokeepthemcozyandcomfortable．

　　Ifyouhaveeverlostsightofyourparentsinacrowdedplayground，youmaybewon-deringhowmotherbatsrecorgnizetheirchildren．Theyusetheirsenseofsmelltotellwhich babyistheirswhenitistimeforthebabiestohavemilk．

　　Whentwentymillionbatsflyoutofonecaveopening，theymakeacolumnsothick thattheyshowupontheradaratthenearbyairport．Itcantakethreehoursforallofthem togetoutfromthecave．"Youcanfeelthebreezefromtheirwings，andseetheplatswa-ving，"saysKennedy．"Themovementofallthosewingsmakesaveryrelaxingsoftsound．I'vealwaysthoughtitwouldmakeagreatrelaxationmusictohelpyougotosleep．Somuch forbatsbeingscary!"

　　56．Thescenedescribedinthefirstparagraphtakesplacein___．

　　A．amovie B．acave C．Mexico D．theUS

　　57．Whatmakesthesceneso"impressive"？___

　　A．Theentranceofadeep，darkcave．

　　B．Thebatsfeedingoninsectsatnight．

　　C．Thehugenumberofbatsflyingtogether．

　　D．Ittakesplaceallsummerlong．

　　58．BothParagraphs3and4aremainlyabout___．

　　A．whenandwherethebatsmigrate

　　B．howyoungbatsareraised

　　C．whybabybatscrowdtogether

　　D．howmotherbatsfindtheirchildren

　　59．Theunderlinedword"breeze"inthelastp