B. A book sitting on a shelf. The books force is going down while the shelf's force is moving up against the book at an equal force.The answer would be B.
Answer:
D. a solid, liquid, or gaseous compound that is found in living organisms
Explanation:
Space surrounding magnet is called the magnetic field. In this field we can encounter magnetic force. Magnet attraction occurs when poles are unlike and is caused by magnetic force. It means that poles should have opposite values.
Answer:
d. Relative humidity increases.
Explanation:
The expression of relative humidity in terms of absolute humidity, absolute pressure and saturation pression at measured temperature is:

When temperature decreases, the saturation pressure decreases also and, consequently, relative humidity increases. Therefore, the right answer is option D.