Earth has a liquid outer core because that's the ocean and the earth is mostly made up by water.The earth has a solid inner by the mantle which is hard rock and made out of gas and rocks and it is very hot out there
Answer:
Melting would have caused denser substances to sink toward the center while less-dense materials would have migrated to the crust.
Explanation:
the world's current population is 7.3 billion and the world population in 1915 was 1.8 billion. The increase over the past century is 7.3 billion - 1.8 billion = 5.5 billion. So, the correct answer would be "more than 5 billion" (option D).
D. Europe, Africa, and North America were the three continents involved in the Triangular Trade
I believe the second answer is B. Oliver Cromwell, but I am not certain