Question

which statement explains something that the fossil record indicates?
earth is still a very young planet
mountains have always existed on earth
mass extinctions have occurred several times on earth
the amount of water on earth has decreased over time.

Explanation:

The fossil record shows evidence of mass extinctions. For example, the extinction of the dinosaurs is well - documented in the fossil record. Earth is not a very young planet (it is about 4.54 billion years old). Mountains have not always existed in their current form (they are formed through geological processes over time). The amount of water on Earth is relatively constant (it is part of the water cycle).

Answer:

Mass extinctions have occurred several times on Earth.