the respiratory digest acting in space from the land
air_bladder is sac. air_path_through_solid is cavity. air_path_through_solid is not cavity. air_respiration is physiological_function. air_bladder is not sac. air_respiration is respiration. air_respiration is not respiration. air_respiration is not physiological_function. respiratory_gas_exchange is not air_respiration. respiratory_gas_exchange is air_respiration.