They got to know with the photographs from the U - 2 spy plane.
<em>Hope this helped! :)</em>
Hi! I think there's no image of the chart but I'd like to answer about the Columbian exchange that might be the answer. The Columbian Exchange started was the widespread of trading of Americans and Afro-Asians and was followed by the voyage of Christopher Columbus to the Americas in 1492. They were exchanging plants, animals, technology, ideas, diseases and human populations.
In the early 19th century, the ruling political party was the Democratic-Republicans. They selected their candidate through a vote of their members in Congress. This system let them control the White House for 20 years. Then the rivalry of John Quincy Adams and Andrew Jackson.divided the Democratic-Republicans into two after the 1824 elections and became Democrats and Whigs.
Answer:
goods production has become increasingly mechanized.
Explanation:
