The nucleus always contains one or more protons.
Answer:
1. to carry oxygen from the lungs to the body tissues
2. seven (7) or (4)
3.Humans can't live without blood body's organs couldn't get the oxygen and nutrients they need to survive,
Explanation:
I'm pretty sure it's Cell membrane
<span>the branch of mechanics that deals with the mathematical
description of the motion and interaction of subatomic particles,
incorporating the concepts of quantization of energy, wave-particle
duality, the uncertainty principle, and the correspondence principle</span>