What type of system is required to maintain the amount of sugar in the blood at a certain level, making sure it does not rise too high or fall too low?

The Digestive system.

Explanation:

Even though the Cardiovascular system pumps the blood in the body, blood sugar is dependent on the regulating hormones insulin and ketone. Which are created in the liver. And the liver is part of the Digestive system. Diabetes, hypoglycemia and hyperglycemia are results of a faulty liver.

cuz they cant breath

explanation:

a. seed plant structure. 1. the three main plant organs are roots, stems, and leaves. a fourth kind of tissue, meristematic tissue, is responsible for plant growth. meristematic tissue is the only plant tissue that produces new cells by mitosis. plants can lose water out of their leaves as they exchange gases with the air

explanation: