At which surface are the cartilaginous rings of the trachea incomplete?

If a tiny particle is placed in the pore of a stoma,what will happen?

The vocal cords are attached to which of the following?

Which one of the following has the smallest diameter?

The lungs of humans and rabbits are . . . . . . .

Select the correct statements about alveoli from the following.
$i$. Air sac of each terminal bronchiole shows $10$ to $12$ alveoli.
$ii$. Each alveolus is surrounded by a network of capillaries.
$iii$. They are lined by ciliated pseudostratified epithelium.
$iv$. They provide surface area for exchange of gases.
$v$. There are about $700$ million alveoli in the lungs.