I would say the U.S. Government is a republican democracy.
I would say alliances and nationalism because nationalism only encouraged countries to go to war and prove that they were the best most powerful country around and in terms of WWI, nationalism led to strong dedication to the army and just keep most countries in the war longer than they should have been in it. Alliances were significant in the exact beginning of the war and the scale to which the war was fought. The many (secret) alliances led to austria-hungary and Serbia to sorta threaten each other, which brought Germany in, then France, etc.
The Amazon river is the longest with 4,345 miles
Neoclassicism was influenced by the Age of Enlightenment or also called as the Age of Reason. Both movements coincide with each other, they started in the 18th century and continue to reign until the 19th.
Neoclassicism is a recovery of the styles and soul of exemplary relic enlivened straightforwardly from the traditional period, which harmonized and mirrored the advancements in rationality and different territories of the Age of Enlightenment, and was at first a response against the abundances of the former Rococo style.