Question

why is the law of gravity an example of a universal law?
gravity exists only on the earth and the moon.
gravity exists between any two masses.
gravity exists between small masses in an open system only.
gravity exists for masses in a closed system only.

Explanation:

The law of gravity is universal because it applies to any two masses in the universe, regardless of the system (open or closed) and the size of the masses.

Answer:

Gravity exists between any two masses.