Answer:Many thousands of years ago, not a single human being lived in the Americas.
This only changed during the last Ice Age. It was a time when most of North America was covered with a thick sheet of ice, which made the Americas difficult to inhabit.
But at some point during this time, adventurous humans started their journey into a new world.
They probably came on foot from Siberia across the Bering Land Bridge, which existed between Alaska and Eurasia from the end of the last Ice Age until about 10,000 years ago. The area is now submerged by water.
There is still debate about when these first Americans actually arrived and where they came from. But we are now getting closer to uncovering the original narrative, and finding out who these first Americans really were.
Explanation:
<span>The share of people in the labor force involved in agricultural work has not only declined, it has declined dramatically over the last century. Although agricultural employment had already been in gradual decline from its peak, the widespread introduction of the mechanized tractor and combine in the 1920s caused a sharp decline which has continued, though at a slower pace, to this day. Currently about 2% of the workforce is engaged in agricultural production, down from 50% a century and a half ago.</span>
After Qin Shi's was killed in 207 BC the dynasty collasped totally because the power was too centralized.
