Answer:
The answer is Carbon.
Explanation:
Carbon is the basic element where the most energy is stored and used as a fuel.
I think it should be D. A loss in biodiversity due to catastrophic event.
Answer:
Major circulation or systemic circulation
Explanation:
It is the process when our heart expulses blood of a chamber called left ventricle and moves to aortic artery and then the blood goes to arterioles and capillaries supplying the oxygen and nutrients that every cell in our body needs.