Answer: They act casually and go about regular business, such as smoking, while actually in grave danger.
Explanation:
The men here are acting casually. They are talking and smoking even though they are about to go out for an attack. This shows bravery in these men because they have accepted what they must do and have reduced their anxiety.
This makes them Hemingway heroes because Hemingway believes that men who participate in dangerous activities with a certain ease and bravery are worthy of the term, hero.
