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.

Arrange the given steps by which the lungs show inspiration,in the sequence of events occurring first:
$I.$ Increase in the volume of the thoracic chamber in the dorsoventral axis
$II.$ Upward and outward movement of the ribs
$III.$ Contraction of intercostal muscles
$IV.$ Entry of air inside the lungs
$V.$ Contraction of the diaphragm
$VI.$ Increase in the volume of the thoracic chamber in the anteroposterior axis
Choose the correct option.

$A$: 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.

Bucket-handle movement is seen in

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

Which one of the following is a possibility for most of us in regard to breathing,by making a conscious effort?