In what way did the United States contribute to end World War I (check all that apply):  
-They supplied the allies with weapons. 
-The peace treaty, authored by representatives of the United States, was signed by Austria-Hungary and Germany and immediately ended the war. 
-Prior to the war, U.S. forces trained France and Russian troops to prepare for potential confrontations. 
-U.S. troops aided the Allied Powers on the battlefield. 
-U.S. citizens gave up food or gas to help in the war effort.