I think the answer is A because it is gravity that caused the planets to form and start orbiting around the nearest star which is the sun
Answer:
The focal length of a lens is refers to the distance from the center of the lens to the principal foci.
The sensation of a frequency is commonly referred to as the pitch of a sound. A high pitch sound corresponds to a high frequency sound wave and a low pitch sound corresponds to a low frequency sound wave. ... That is, two sound waves sound good when played together if one sound has twice the frequency of the other.
