Directions (66–85): record your answers in the spaces provided in your answer booklet. some questions
may require the use of the 2011 edition reference tables for physical setting/earth science
base your answers to questions 66 through 69 on the graph below and on your knowledge of earth science.
the graph shows changes in hours of daylight during the year at the latitudes of 0°, 30° n, 50° n and 60° n.

explain why all four latitudes have the same number of hours of daylight on march 20 and september 22.

the first phase of the government’s plan for settlement was building the transcontinental railroad. the railroad provided a way to bring settlers and manufactured goods west and ship their agricultural and mining produce east. the transcontinental railroad was an essential artery for rapid development of the frontier.

the second phase of the government’s plan was a liberal land distribution policy that made it possible for many people to homestead. with these two key elements—transportation and cheap land—the government rapidly achieved its goal of persuading people to move west, settle on farms, and push back the frontier.