How did Muslim hospitals change medicine? They developed new methods of solving math problems.
They helped doctors study diseases and improve medicine.
They translated important works of medical scholarship into Arabic.
They sent doctors out of the area to study and bring back knowledge.

just need the points

explanation:

c]extended voting rights to african americans

answer: the time zones used to be whatever the local authority wanted them to be. one town might have 6am whenever the sun came up and another town had 6am 10 minutes later.  

the trains had a hard time when their orders said to be at a certain point at 6am.  

6am, but who's 6am.  

the railroads got together and set the time zones more or less along the longitude lines across the country.

explanation:

to protest slavery i would think it would be a