B I just took it so it’s b
The nervous system consist of the brain, spinal cord and nerve fibers. Exercise Improves the brain
Depends on how fast he runs in a sitting. If he runs slow during the 20 minutes he isn't getting much done :D.
I believe B is the correct answer
Hope this helps
-DunFlowers
Please note I can only make out some of this, so here's the answers I can see-
Answer #5:
Left atrium, right atrium, left ventricle, right ventricle.
Answer #10:
1.2-1.5 gallons.
Answer #8:
White blood cells fight and kill off diseases.
I'll add more as I get it
EDIT!
Answer #4:
They assist in clotting your blood
Answer #14:
O, B, A, AB.
