Birdsknowwheretogowhenit’stimetomigrate.Theygetsomeofth...
问题详情：Birdsknowwheretogowhenit’stimetomigrate.TheygetsomeofthatsuperbsenseofdirectionfromtheirabilitytospotEarth’smagneticfield.Thatmagneticsenseactsabitlikeacompassusedbyhumanhikers.Buttheenergyc...