Why the heart needs two types of pump

because the first pump carries oxygen-poor blood to your lungs, it unloads carbon dioxide and picks up oxygen, the second pump delivers oxygen-rich blood to every part of your body

Explanation:

Your heart is a single organ, but it acts as a double pump. The first pump carries oxygen-poor blood to your lungs, where it unloads carbon dioxide and picks up oxygen

Then delivers oxygen-rich blood back to your heart. The second pump delivers oxygen-rich blood to every part of your body.

Hope this helped!

stratosphere: as the altitude increases, the air temperature increases. the stratosphere has a layer of ozone, called the ozone layer. this layer absorbs most of the ultraviolet radiation from sunlight. this results in the stratosphere being warmer.