Along which rivera did major agricultural societies emerge

How did the completion of the transcontinental railroad change the lives of american citizens? a-it increased the wealth of all americans and enabled them to travel more.b-it made cross-country travel too expensive for ordinary americans.c-it decreased the safety of americans who moved to settle the plains.d-it shortened travel time between the east and west for all americans.

What are the biggest challenges facing the average american citizen today? explain.

56: 58 the assembly line was a system through which items were mass-produced in a flow.