The base 20 numbering system was invented and used by the aztecs incas han mayans

How did testimony such as this from the triangle shirtwaist factory disaster affect the workplace?

Experimented with communism before taking part in a number of civil rights and antiwar protest

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.