Which substance is not a fossil fuel?

Explanation:

Biogas

Biogas is the mixture of gases produced by the breakdown of organic matter in the absence of oxygen, usually consisting of certain quantities of methane and other constituents. Therefore, biogas is not a fossil fuel.

58750.08068 is the answer i think

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.