Question

why is the lungs of birds than the lungs of human
in two lines ​

Answer 1

In addition, the bird lung has a “cross-current” gas-exchanging system, which is believed to be more efficient than that in the human lung. ... This is one reason why the alveoli in the human lung are much larger than the air capillaries in the bird lung; human lung alveoli are approximately 0.3 mm in diameter.