Drinking water shortages? Water across the world isn't purified which without purification doesn't quench thirst.
Answer:
little pouches
Explanation:
the aleveoli are like small balloons, but not large ones. they exchange oxygen and carbon dioxide molecules (so they contain small amounts of air like a SMALL balloon, or in this situation a small pouch).
Supply oxygen to cells for cellular respiration.
Answer: C the Montgomery bus boycotts is a prime example