The answer is two and a half years.
The United States watched World War I from afar for two and a half years before entering and declaring a war against Germany on April 6, 1917. Before entering the war, United States was intent on keeping a neutral relationship between countries that are involved in the war.
The United States really didn't want to get involved in either of these wars, however the decision to enter WWII was far easier since the Japanese bombed Pearl Harbor. After WWI, the Us become havily isolationist, while after WWII they were forced to be more engaging since the Col War was underway.
Answer: B, He refers to American radio stations that broadcast rumors sent by the Axis powers.
Answer:
the development of new navigational instruments and technology
hope that helped <3
