Interchangeable parts and assembly line
The average temperature are highest near the equator and get colder toward poles.
Federalism because it simply states that in the text
Manifest Destiny summary: In the 19th century US, Manifest Destiny was a belief that was widely held that the destiny of American settlers was to expand and move across the continent to spread their traditions and their institutions, while at the same time enlightening more primitive nations. And the American settlers of the time considered Indians and Hispanics to be inferior and therefore deserving of cultivation. The settlers considered the United States to be the best possible way to organize a country so they felt the need to remake the world in the image of their own country.
B because during the 1200s and 1300s, the Mongol took over most of Afro-Eurasia. It was unexpected because they were a nomadic group.
A is wrong because serfdom implies the feudal system only seen in Europe and Feudal Japan.
C is wrong because the European Crusaders pretty lost every Crusade to the Muslims. The outcome of the Crusades were Europe's increased interest in Islamic goods.
D is wrong because the Byzantine Christians didn't do the Crusades, the Holy Roman Empire did.
