Answer:
Arteries carry oxygenated blood away from the heart. Veins carry the blood back to the heart. Veins contain valves that ensure blood flows in only one direction. Arteries don’t require valves because pressure from the heart is so strong that blood is only able to flow in one direction.
Explanation:
Answer:
Your body has different kinds of cells. Though they might look different under a microscope, most cells have chemical and structural features in common. In humans there are about 200 different types of cells and within this cells there are about 20 different types of structures or organelles.
The answer is b, for he is comparing the two rocks to find an age relative to the other
The scientific term of a fat cell is an adipoctye.