Hello! The answer to your question would be as followed:
The process of becoming a US citizen when you are not born in the united states or to parents who are US citizens is called <u><em>"The Naturalization Process"</em></u>
Europeans couldn't travel into the interior of Africa in order to take it over because of the African-ruled trade, couldn't navigate violent rivers, or overpower their strong armies. Disease also held them back.
radiation I believe that is it
