The answer here is that you should have put a question for me to answer.
Answer:
c more highly skilled workers were needed.
<span>The Americas were the last (well, second-to-last if you count Antarctica) continents to be inhabited by early humans. Archaeologists estimate that people entered North America by crossing over the Bering Strait, which back then was a wide swath of land, about 15,000 years ago.</span>
