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 phenomenon is crowding out other species and making all the other causes of extinction worse? Answer: human overpopulation

A: Human overpopulation, which is crowding out other species. It also makes all the other causes of extinction worse.
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Q: Question: What cells carry oxygen? Answer: red blood cells

A: Red blood cells carry oxygen, white blood cells defend the body, and platelets help blood clot.
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Q: Question: What is it called when rays focus at different distances from the lens? Answer: spherical aberration

A:
Figure 26.30 Spherical aberration is caused by rays focusing at different distances from the lens.
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