They check there answers using history, like they use primary sources etc.
One cause is that many powerful nations were longing for war because of the distrust they had amongst each other. In the words of Otto Von Bismarck, “Europe is a powder keg about to explode, and it’s leaders are smoking right above it”.
Another reason was the assassination of archduke Franz Ferdinand. The future prince of the Austrian-Hungarian Empire being killed by a man from Serbia caused outrage and spewed into all our war. The third reason was the fear of an expanding German Empire. When the German Empire was formed after the Franco-Prussian war, they were close allies with Germany because of Otto Von Bismarck, however, Prince Wilhelm fired Bismarck and cut ties with Britain by building a large navy of their own that would challenge The United Kingdom’s dominance over the seas. France has been longing for revenge after the humiliation at the Franco-Prussian war, and the Kingdom of Russia wanted to protect its title as “Protector of the Slavs” in Eastern Europe, so defending Serbia was a good idea, they also wanted to project their strength.
Recycle and natural resources
Answer:
You didn't include a list so I'll just copy n paste the territories that they did acquire. "As a result of the war, the United States acquired Puerto Rico, Guam, and the Philippines as territories."
