Question

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

Answer 1

Hey Dear here is your Answer =)

*Lungs don't collapse even after forceful expiration....This is due to the presence of C-shaped cartilaginous rings which gives support to the trachea and prevents it from collapsing....

Hope it helps you out =)
Thanks (^^)

Answer 2

the lungs cannot collapse every after Force full because this is due to presence of c ship
don't smoke cigarettes.