The overall specific gravity of the earth is much higher than the specific gravity of crustal rocks which means the earth is about twice as heavy as the rocks on the surface would suggest. Iron meteorites are thought to have the same composition as the average earth, and the meteorites contain a lot more iron than the Earth's surface rocks.
They most likely have faculties that treat ocean water.
True, the Earth's axis runs from the north pole to the south pole.
I believe the basement is the best answer
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