Answer: 1.the great war and its aftermath
Step-by-step explanation:
Ernest hemingway was recruited by the Red Cross in Kansas during World War I and he was assigned as an ambulance driver in Italy he witnessned violence, bloody battles and life and death situations which provided him with rich sources for writing. In his works the protagonists often suffer physical and psychological pains. Francis Scott Key Fitzgerald in 1917 dropped out of school to join the U.S. Army. In the weeks before reporting to duty, Fitzgerald wrote "The Romantic Egotist" while in fear that he might die in World War I.