What is the shape of the diaphragm during expiration?

Breathing involves ...$A$... during which atmospheric air is drawn in and ...$B$... by which the alveolar air is released out.
Choose the correct option for $A$ and $B$ to complete the given $NCERT$ statement.

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

What happens to the volume of the pulmonary cavity when there is an increase in the volume of the thoracic chamber?

Select the correct statement.

If a person breathes with maximal effort but with his nose and mouth closed,the alveolar pressure can be decreased to as low as