Birdsknowwheretogowhenit’stimetomigrate.Theygetsomeofth...
問題詳情：Birdsknowwheretogowhenit’stimetomigrate.TheygetsomeofthatsuperbsenseofdirectionfromtheirabilitytospotEarth’smagneticfield.Thatmagneticsenseactsabitlikeacompassusedbyhumanhikers.Buttheenergyc...