The answer would be b) push factors
North America is one of three continents (along with South America and Oceania) that make up the "New World." The continents were new to 15th-century European explorers, but old to the indigenous people living ther
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A pearl harbor that was what led the U.S. to join WWII
Population density is the number of people in a certain unit of area which is typically calculated as square miles
So a high population density would mean there is a large number of people in one square mile