Human migration is the movement of people from one place to another with the intention of settling in the new location. When large numbers of people relocate, historians ask questions about why these people moved and what impacts their movements had.
Answer:
The continuous process in which hot, molten material coming to the surface of the Earth from the interior forms igneous rocks, which are then broken down by weathering to create soil and sedimentary rocks.
I think 1991 it was the fall of soviet union
