You should always keep calm and try to think positive never put your self down never ever
You should start studying a week before
2and3 only are the defense
Answer:
Adaptations of the alveoli:
Moist walls - gases dissolve in the moisture helping them to pass across the gas exchange surface. Permeable walls - allow gases to pass through. Extensive blood supply - ensuring oxygen rich blood is taken away from the lungs and carbon dioxide rich blood is taken to the lungs.