Question

Why don't the lungs collapse even after forceful expiration?

Answer 1

Yo!
I hope that this the answer you are looking for,bud,
This is due to the presence of C-shaped cartilaginous rings which gives support to the trachea and prevents it from collapsing.Plus,there will always be some small amount of air,in our lungs,no matter how hard you try to breathe out forcefully.
Hope it helps ya!

Answer 2

Answer:

lungs do not collapse even after forcefull expiration because our lungs will never become empty. there will always be some amount of air inside the lungs called residual volume which prevent them from getting collapse.

please mark my answer as brainiest.