Which item could serve as a secondary source for a historian studying early
Chinese history?

b. she founded a new dynasty that ruled egypt for generations.

the answer is c.

i hope this .

demand is the need and oportunity to buy a given good or service.

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: