First thing that comes to mind is maybe withdrawing too much money (overdraft fee).
U-boats were military submarines used by the Germans. While they were useful against warships, U-boats were the most effective in economic warfare by blockading coasts so resources could not be shipped to Germany's allies. WWI was the first major war that employed submarines in warfare.
Please mark brainliest if this helped :)
A national border. Long river.
Monarchy beacuase that is a type of goverment.
