Answer: They indicate that Passini feels passionately about his beliefs.
Step-by-step explanation:
Hemingway´s novel, first published in 1929, is a first-person description of an American, Frederic Henry, working as a lieutenant in the ambulance corps of the Italian Army during the Italian campaign of World War I. Passini and Bonello are the ambulance drivers serving under Henry.
Passini is passionately against the war and openly protests against it. Passini wants the war to end, and has decided not to fight in it anymore.