Why did Europeans suddenly need to buy slaves from Africa?

What are two things china and canada have in common

Plz . explain what shopping was like in london during the early 1900s. how does this differ from the modern shopping experience?

How did the united states respond when north vietnam attacked a us warship and sent troops to south vietnam in the early 1960s? a. the united states declined to assist south vietnam against the north. b. us leaders authorized south vietnam to invade north vietnam. c. the president did not sign the gulf of tonkin resolution. d. congress authorized the president to escalate the conflict.