This feature is made by wind... a) waterfall

b) cirque

c) sand dune

d) delta

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 was istanbul called before he ottomans conquered the city in the 15th century

:calculate the sum of the interior angles of a 13-sided polygon.