750 million years ago, there was enough Uranium-235 present in Oklo, Gabon to have a natural fission reacton occur and generate a chain reaction. If there is currently 50kg of U-235 present in Oklo, how much must have been present 750 million years ago when the reaction took place? A) 50 kg B) 100 kg C) 200 kg D) 375 kg B 100kg because i put 50 and it was wrong.

explanation:

venn diagram is pictorial representation with of circles showing the relation between two finite sets or things. the intersection part of two circles conveys the relation present in between those sets or things.

here in the venn diagram of sand and salt two circles represent sand and salt. but the area falling under the intersection of these circle represents the mixture of sand and salt.

so, in a venn diagram the mixture will be placed in a middle that is in between the intersection of two circles.

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.