Organisms which have hollow bones and have the ability of flight belong to the class
Amphibia
Pisces
Reptilia
Aves
Column I Column IIa) Pisces1.Gills in larvae, lungs in most adultsb) Amphibia2.Have mammary glandsc) Reptilia3.Have wings for flightd) Aves4.Breathe through gillse) Mammalia5.Have dry scales on the body