Comparing the two TLC runs on the three compounds together (runs #1 and #2), you should have noticed that in one case, one compound eluted in "first place" while in the other run, a different compound eluted in first place. Suggest a reason why this might occur.

it would be a gas formation

b. is the answer hoped i        

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.