Answer:
The Constitution's Supremacy Clause prohibits state governments from passing laws that conflict with federal laws and also prohibits any entity from enforcing laws that conflict with the Constitution. This protects enumerated powers, which are federal government powers that are specifically set out in the Constitution.
Increase of nationalism and capitalism and militarism increased competition
The Black Sea and Aegean Sea (Hopefully this is correct!)
In the Gibbon Passage, the natural disaster that struck the Roman Empire in 366 CE was a violent and destructive earthquake, followed by a huge tsunami which killed many people.
