Answer:
the layer of the planet Earth where life exists
Explanation:
The second diagram best represents regeneration
The tricuspid valve, located between the right atrium and the right ventricle; the pulmonary (pulmonic) valve, between the right ventricle and the pulmonary artery; the mitral valve, between the left atrium and left ventricle; and. the aortic valve, between the left ventricle and the aorta.
<span>The atomic mass is the number of protons plus the number of neutrons in an atom.</span>