Respuesta :
B
explanation: each bird flys slightly above the bird in front of him resulting in a reduction of wind resistance. The birds take turns being in front & falling back when they get tired so they can fly for a longer time without rest
explanation: each bird flys slightly above the bird in front of him resulting in a reduction of wind resistance. The birds take turns being in front & falling back when they get tired so they can fly for a longer time without rest