Why couldn’t the Europeans use Native Americans as slaves?

During what century did muhammad recieve his first revelation from god

"if i have seen farther than others," said newton, "it is because i have stood on the shoulders of giants." who were the giants to whom newton was referring? could this be said of any scientific accomplishment? explain.

Which of the following statements about slavery is not accurate? a. slavery in the americas was no different than slavery in ancient greece or rome. b. beginning in the 1600s, slaves began to be viewed as property, rather than people. c. slavery did not originate in the americas. d. slavery was very important to the economy of the american colonies.