Several of theses molecules connected in a chain reaction in a/an

Which of the following is the earliest era of earth's geologic time scale? cenozoic mesozoic precambrian paleozoic

Consider the equation s + o2 ? so2. what is the product? question 3 options: s so 2 s + so 2 o 2

In general, characteristics that an organism survive and reproduce become more common in a population over time. what mechanism of evolution cause this change?