I would say the agricultural aspect of how the Mayans grew their crops. I learned this unit just a few months ago and even a bit before. This article has a lot on the Mayan culture.
Source: www.history.com/topics/maya
John D. Rockefeller went into business when he was 20, and he picked up his first oil well as a sideline. He soon saw that that was the right horse to ride. Even before automobiles and airplanes laid their heavy claim on oil, it'd begun replacing coal in the power industries.
Andrew Carnegie makes the better hero. He, after all, was part and parcel of the emerging technologies that made our country. And his giving sprang from some deep-seated core of principle. Yet the Rockefeller clan assumed the mantle of public service. They've become political leaders and professional givers -- one died doing anthropological research in New Guinea.
The answer should be B! It's actually kinda funny. Northerners thought that the Confederate army would be easily defeated and that the Civil War was going to begin and end at the Battle of Bull Run. So, lots of spectators watched, but they were quickly proven wrong, as the war lasted for years.
C. states needed to be given more control
