Naval warfare.
Land warfare.
Artillery.
Chemical warfare.
Mobile warfare.
Aerial warfare
Because they knew that Germans could sink any ship they want. They could sink civilian ships. Back then, the only way to travel long distances was by boat, because passenger airplanes had not been invented. The Germans could now sink them if they wanted to travel somewhere, so they either risk their life or not go on trips.
Because it didn’t receive support from the senate. Also the U.S wanted to keep America out of European affairs.
Those people believed in the Mandate of Heaven, they thought that God selected the legitimate ruler. So, the Zhou claimed that the Shang were not chosen by God, and therefore, be overthrow-ed, the answer would be 1