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.

[EX Q]: Question: Timber, medicines, dyes, oils, and rubber are just some of the useful products humans derive from what? Answer: plants
[EX A]: Plants provide many products for human use. They include timber, medicines, dyes, oils, and rubber.

[EX Q]: Question: Hair and nails are made of what? Answer: keratin
[EX A]: Hair and nails are made of keratin, a tough protein.

[EX Q]: Question: The energy for an ecosystem can come from sunlight or _________? Answer: chemical compounds
[EX A]:
All ecosystems need a constant input of energy in the form of sunlight or chemical compounds. Living things can be classified based on how they obtain energy as producers, consumers, or decomposers.