How do scientific advancements allow the historical community to create a time frame to when people began to populate the Americas?

d.he wanted to send diplomats to communist countries.

in 1897, pershing became a tactical officer at west point, and that's where he was given the nickname "black jack." pershing's first name is "john," for which "jack" is a nickname, and he was a white man who commanded black troops. hence "black jack".

the foundation of greek city-states: following the fall of the mycenaean civilization in the 10th century bc, the area surrounding the empire went through its own mini dark ages. answer and explanation