~ C. Population
Population is all the inhabitants of a particular town, area, or country.
Answer:
It is a good concept but can't be used.
Explanation:
Producing artificial blood is a good concept but it can't take the place of real human blood because the artificial blood has many disadvantages which can cause great damage to our body such as binds nitric acid that affected blood flow, increases the level of bilirubin, amylase and lipase in the blood and also cause overload of iron in your organs or tissues so that's why it can't be used instead of original human blood but may be in the future if these complications are removed.
Answer:rabbits
Explanation:an owl or fox can kill the rabbit and eat it
The respiratory system regulates oxygen flow, and provides regulation for oxygen blood content. Circulatory system plays a roll in providing enough oxygenated blood to the body
