The theory of sea floor spreading, was found too simplistic because it did not explain how the continents would move. It was replaced by a theory called

What is the northern most national park in the world

Name the two rivers that run through the fertile crescent. how were the rivers both positive and negative to societies of the fertile crescent?

The first atomic explosion was detonated in the desert north of alamogordo, new mexico, on july 16, 1945. what percentage of the strontium-90 ( yr) originally produced by that explosion still remains as of july 16, 2016?