Finding where the Missouri and Columbia rivers link/join and go into the Pacific Ocean as it didn’t exist
Compared to time in earth's history before humans appeared, rates of soil erosion are "higher", due mostly to the fact that some human activity associated with building structures adds to this erosion.
Naturalization is the process of becoming a citizen of a country where you don't come from. After you naturalize, you get the rights and responsibilities of being that country's citizen.
I believe it is D, Island hopping.
Cotton gin, steam engine, and I seriously can't think of a third.
