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: When waves of two different frequencies interfere, what phenomenon occurs? Answer: beating

Output: When waves of two different frequencies interfere, a phenomenon known as beating occurs. The frequency of a beat is the difference of the two frequencies.

Input: Consider Input: Question: Water molecules are polar, so they form what type of bonds? Answer: hydrogen

Output: Water molecules are polar, so they form hydrogen bonds. This gives water unique properties, such as a relatively high boiling point, high specific heat, cohesion, adhesion and density.

Input: Consider Input: Question: The lungs, kidneys, skin, and large intestine are all part of what organ system? Answer: excretory
Output: Organs of the excretory system include the kidneys, large intestine, skin, and lungs.