instruction:
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.
question:
Question: Water, carbon dioxide, and what other element are important agents of chemical weathering? Answer: oxygen
answer:
Water, carbon dioxide, and oxygen are important agents of chemical weathering.

question:
Question: Pressure, volume, and temperature are related by which law? Answer: gas law
answer:
Pressure, volume, and temperature are related by the combined gas law.

question:
Question: What is the part of the shadow that is partially lit called? Answer: penumbra
answer:
The penumbra is the part of the shadow that is partially lit.