What geographic features kept the ancient Greeks from being united?

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.

4. any area in which one nation has power over another; i. e. - this happened to china when it was defeated by japan

Which of the following statements is true of cause and effect relationships