Select each correct answer.
by comparing fossils in higher sedimentary layers with fossils in lower sedimentary layers, scientists can learn which of the following?

select one or more:
a. the relative age of different species
b. which types of organisms were more common during various time periods
c. how species have evolved over time

A.

Explanation:

because if they are at different layers in the ground that must mean that they died differently. Which also means that they died at different times which means that they are different amount of years old.

chlorophyll a: this is the most abundant pigment in plants. chlorophyll a absorbs light with wavelengths of 430nm(blue) and 662nm(red). it reflects green light strongly so it appears green to us.

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.