Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.

Input: Consider Input: Question: Mixtures of materials called alloys contain at least one of what type of material? Answer: metal

Output: Alloys are mixtures of materials, at least one of which is a metal.

Input: Consider Input: Question: Frequency and intensity are two measurable properties of what? Answer: wave

Output: All waves can be defined in terms of their frequency and intensity.

Input: Consider Input: Question: By what kind of change can a chemical change be reversed? Answer: another chemical change
Output: Because chemical changes result in different substances, they often cannot be undone. Some chemical changes can be reversed, but only by other chemical changes.