Question

describing the geologic time scale
select the correct responses to the questions from the drop - down menu.
what did scientists study to develop the geologic time scale?
which division of the geologic time scale includes most of earths history?

Explanation:

Scientists developed the geologic time scale by studying rock layers and fossils. The Precambrian eon includes most of Earth's history.

Answer:

What did scientists study to develop the geologic time scale? Rock layers and fossils.
Which division of the geologic time scale includes most of Earth's history? Precambrian eon.