Answer:
A)The temperature of the air increased, and the difference in pressure between the low pressure and the high pressure systems became small.
Answer:
they are not affected by earth atmosphere
Answer:
They have a gizzard to grind the food.
Explanation:
Birds cannot chew since they have no teeth. However, the beak allows them to split very large seeds or swallow them directly.
For their digestion they have a stomach where digestion enzymes are released. Also they have a gizzard that is an organ that grinds the food mechanically. This gizzard usually has small stones inside that were previously ingested and that helps to digest the food.