Acertain ore is 29.9% nickel by mass. how many kilograms of this ore would you need to dig up to have 75.0 g of nickel?

it should be all of them because it asks if you included all of those in your answer

explanation:

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.