Question

which of these facts is supporting evidence that the universe is expanding? the universe is filled with galaxies of different sizes. the galaxies can spin to form eddies. the stars vary in chemical composition. the galaxies are moving away from each other.

Explanation:

The fact that galaxies are moving away from each other is a key piece of evidence for the expansion of the universe, as described by Hubble's law. The other statements are about the content, motion - related eddies, and chemical composition of stars or galaxies, which are not directly related to the expansion of the universe.

Answer:

The galaxies are moving away from each other.