Which is the most important muscular structure in the respiratory system of a rabbit?

Hiccups are caused by the activity of which of the following?

In mammals,the ventilation movements of the lungs are governed by:

What is the most important function of the diaphragm in mammals?

$A$: Normal expiration during quiet breathing,unlike inspiration,is a passive process because no muscular contractions are involved.
$R$: Normal expiration results from the elastic recoil of the chest wall and lungs.

Select the correct option for the given figure (assuming the figure shows expiration).