To prevent blood flowing back after each heartbeat. They ensure that the blood flows only in one direction (back to the heart).
Because they are the essential micronutrients for the different metabolites of living organisms?
The magnetic field of a bar magnet is the strongest at either pole of the magnet. It is equally strong at the North Pole when compared with the south pole. So I would say the answer is A.
Answer:
false
Explanation:
"Electrons are the "material" of the charge that is flowing. Therefore, current can never cause a metal object to become positively or negatively charged, because the net number of electrons in the metal object will never change due to current flow."