Consider the last 400 years of history, was the Columbus Exchange mostly positive or negative for Europe and for the Americas and why?

What is the purpose of the system of checks and balances

Which of these statements describes a long-term impact of european imperialism in africa? a. african countries joined together to present a united front against imperialism. b. europeans paid african countries after colonizing them, offering these new countries a fresh start. c. european powers drew the current borders, splitting ethnic groups among modern countries. d. africans became more loyal to their countries than to their ethnic groups.

By july of 1950 north korean forces had pushed south korean forces as far south as