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.

[Q]: Question: Different media affect what property of light? Answer: speed
[A]: The speed of light is different in different media.

[Q]: Question: Lactic acid fermentation is common in muscle cells that have run out of what? Answer: oxygen
[A]: Figure 7.14 Lactic acid fermentation is common in muscle cells that have run out of oxygen.

[Q]: Question: Most people can survive only a few days without what essential substance? Answer: water
[A]:
Water is essential to life because biochemical reactions take place in water. Most people can survive only a few days without water.