Why were certain foods rationed during world war 2

Which statement does not accurately describe the columbian exchange and its consequences? a. wheat became a major crop in north america where it had never existed before. b. millions of africans were kidnapped into slavery to provide labor for profitable crops. c. cattle, sheep, chickens, and pigs were brought to europe for the first time. d. spanish conquistadors brought diseases with them and native peoples begin dying.

What is zinn's approach to the study of history? what does he suggest occurs when history is told is the story of human progress?

What enabled the drastic increase in us troop development to vietnam between 1964 and 1965?