Why was the Cumberland Gap a good place for a trail?

In 1915 the german geologist and meteorologist alfred wegener first proposed the theory of continental drift, which states that parts of the earth's crust slowly drift atop a liquid core. the fossil record supports and gives credibility to the theories of continental drift and plate tectonics.

What two properties affect the density of ocean water

What does the map above tell us about the endemity of typhoid fever