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: What is the strength of an earthquake called? Answer: magnitude
[A]: Earthquake: What Does Magnitude Mean? at http://www. livescience. com/20538-earthquake-magnitude-video. html (2:00).

[Q]: Question: What type of tissue makes up much of the inside of a plant? Answer: ground tissue
[A]: Ground tissue makes up much of the inside of a plant. The cells of ground tissue carry out basic metabolic functions and other biochemical reactions. Ground tissue may also store food or water.

[Q]: Question: The most magnetic material in nature is what? Answer: magnetite
[A]:
Some materials are natural permanent magnets. The most magnetic material in nature is the mineral magnetite.