<span>The geologic time scale is divided into periods, which are then divided into epochs, which are further divided into ages. For example, the time of the dinosaurs lasted 3 periods (Triassic, Jurassic, Cretaceous), each period had 3 epochs (late, early, middle), and each age fit into one of those. Many epochs have more than 1 age associated with them.
As for the basis for differentiating the eras, I'm not so sure. The only one I can say for sure is the end of the Cretaceous, which is when the dinosaurs suddenly became extinct due to a meteor impact. I think the divisions are based on significant, global-scale events that changed the world.
Sorry its so long but that the answer i think >:) ur welcome
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Answer: The cell is the structural and functional unit of all living organisms, and is sometimes called <u>the "building block of life."</u> Some organisms, such as bacteria, are unicellular, consisting of a single cell.
I think the answer is a red color
The answer is b, for he is comparing the two rocks to find an age relative to the other
