The flightless bird,cassowary,is found in:

The forelimbs are modified into wings in

Identify the correct statements regarding class $Aves$.
$I$. Forelimbs are modified into wings and hindlimbs are modified for walking and swimming.
$II$. Heart is completely four-chambered.
$III$. They are homeotherms.
$IV$. They are oviparous and development is direct.

The largest living flightless bird is:

What type of sternum is found in birds?

Assertion $(X)$: Birds can consume food very quickly.
Reason $(Y)$: They possess a crop.