Answer:
And unless people interfere, thermal energy — or heat — naturally flows in one direction only: from hot toward cold. Heat moves naturally by any of three means. The processes are known as conduction, convection and radiation. Sometimes more than one may occur at the same time.
Explanation:
Answer:
Muscular system--helps the body move.
Skeletal system-- provides structur to the body.
circulatory system-- circulates oxygenated blood through the body.
respiratory system-- exchanges gases in the body.
integumentary system-- helps receive signals from the outside world.
One is pulmonary one is cellular
The answer seems like water. We're made up of 70% of water & many of the chemical reactions necessary for live need water as a reactant or a solvent.
Hope that helps!