Question

How are the alveoli design to maximise the exchange of gases

Answer 1

alveoli are balloon like when the exchange of gases do not take place they are like balloon with no air and when gases exchange take place they are shaped as balloon with filled air
Hope it was helpful:-)

Answer 2

It has large surface area for the exchange of more and more blood and it is richly supplied with blood vessels for easy transportation of blood and it's walls are thin for the easy exchange of blood