Answer:
Blood vessel, a vessel in the human or animal body in which blood circulates. The vessels that carry blood away from the heart are called arteries, and their very small branches are arterioles. Very small branches that collect the blood from the various organs and parts are called venules, and they unite to form veins, which return the blood to the heart. Capillaries are minute thin-walled vessels that connect the arterioles and venules; it is through the capillaries that nutrients and wastes are exchanged between the blood and body tissues.
Explanation:
<u>Answer:</u>
Theory is used to describe a fact that has always been observed true but could at some future time not be observed as true.
Option: (B)
<u>Explanation:</u>
- Hypothesis is a guess that is based upon the observation. Hypothesis is an idea that might occur in future but doesn’t fall in present theory.
- Generally hypothesis is not based upon facts and also they aren’t proved. Interpreting certain fact is theory.
- Theories are only the explanation of something but facts is observable.
- Theory is something like a concept or idea that is observed to be true at present may fail in near future.
- Law is absolute and true. Generally, they are represented by mathematical expression or equation.
- For example, Newton's law, Law of gravity, Law of thermodynamics.
The answer would be letter a
