The history of the earth is measured in time.

central

geological

coastal

What did not occur in the proterozoic eon a)the oxygen levels increase greatly in the atmosphere, b)the emergence of the eukarya , c)muti cella’s eukaryotic organisms began to diversify, d)anaerobic bacteria kept thriving with more oxygen

In each transformation of energy , some energy what?

What materials must dams have to produce electricity, and what must occur?