Answer:
Defletion hollows: Defletion hollows are ever wind has removed sand down to a level where a layer of particles is too heavy for the wind to move stabilises the sand and prevent the surface being lowered further. It's also known as blow out dune.
Explanation:
Sorry ,I only know about this so i can't tell u of others
I think the answer is number <span>3. Due to Europeans overpowering native populations
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Most of the Native Americans would rather marry someone for their own tribes. Though some of the Natives don't have an aversion towards some Europeans, their culture does not allow them to mix blood with the Europeans.
Well the Soviet Union used to occupy 1/6 of the earth's surface. I could be wrong.