Explain what the columbian exchange was and the changes it had on the world?

What did a letter signed by world-famous scientist albert Einstein communicate to Franklin d roosevelt early in the war? What part of the world is Iraq in? What countries in the Middle East are autocratic? What was the preeminent center of modernism before world war 2? What long-term impact will Cleopatra have on the world? What was the value of 150 Rupees in year 1950? Was Louis Jolliet a European explorer? How did Alfred Nobel change the world? What number is XVI? How do you trace the serial number on a schrade knife? What four lasting effects of the Columbian Exchange? What mistakes did the parliament do? What happened at the Elbe River in 1945? How many Robert's in the world are there? Which country or countries has been at peace the longest at presents? What is a hoggee? Which country took the lead in overseas exploration Why? Why is Andorra's water supply important to the country? What is the cotton kingdom? Did koruna been the same currency?