How did the song improve upon the tang version of the civil service system?
they mandated that most officials came from the military.
they made the examinations easier to pass.
they opened up the system to more people.
they required students to earn their degrees in three years.

The correct option is "They opened up the system to more people. "

The Tang dynasty was the successor of the Sui dynasty and predecessor of the period of the Five Dynasties and the Ten Kingdoms in China. The dynasty was interrupted by the second Zhou Dynasty (690-705), when Empress Wu Zetian usurped the throne and founded her own dynasty. The Tang dynasty, with its capital in Chang'an (present-day Xi'an), the most populous city in the world at that time, is considered by historians as a moment of splendor of Chinese civilization, equal to -or even superior- to of the Han period.

the answer is: the sesquicentennial of the american civil war is an occasion to consider the legacy of that great conflict. this legacy is our inheritance, and despite many indelible features, we continue to negotiate the resolution of that conflict. the civil war was fought over slavery, but not always on behalf of slaves

the right answer is the third one: turnpikes went short distances to connect markets. turnpikes, also known as toll roads, were very important for trade and transportation (of people, goods and products) in the 19th century, coinciding with the expansion towards the west. they contributed significantly to the economic development of the united states.