Answer:
They act casually and go about regular business, such as smoking, while actually in grave danger.
Step-by-step explanation:
In Ernest Hemingway's "A Farewell to Arms", the hero or protagonist of the story is a young Lieutenant Frederic Henry, an ambulance driver for the Italian Army during World War I. He served in the army, helping people and doing deliveries of any type.
The above excerpt from the novel shows the soldiers acting casually, as if the war they are fighting is an everyday issue. They don't seem to mind the gravity of the situation, and the need to fight and prepare to be attacked anytime. They just act casually and go about regular business, smoking and passing it around while being in grave danger at the same time. This action of the soldiers can be taken as a typical characteristic of a hero in Hemingway's novels.