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: Smog is a visible form of what? Answer: air pollution
[A]: Smog clouds the city of Los Angeles, California. Visible air pollution in the form of smog is a sign that the air is unhealthy.

[Q]: Question: Magnetite crystals of different ages and on different continents pointed to different spots. the simplest explanation is that the continents have done what? Answer: moved
[A]: Magnetite crystals of different ages and on different continents pointed to different spots. The simplest explanation is that the continents have moved.

[Q]: Question: Name the plant considered to be the ancestor of plants? Answer: green algae
[A]:
The ancestor of plants is green algae. This picture shows a close up of algae on the beach.