What is the difference between writing "Dear Dr. Williams", or saying "Hey Doc"

Read the excerpt from ernest hemingway’s “soldier's home.” his father was in the real estate business and always wanted the car to be at his command when he required it to take clients out into the country to show them a piece of farm property. the car always stood outside the first national bank building where his father had an office on the second floor. now, after the war, it was still the same car. nothing was changed in the town except that the young girls had grown up. how does hemingway’s description of the town as unchanged impact the readers’ perception of krebs? it emphasizes that while the town has remained the same, krebs has changed. it illustrates that krebs despises the town he grew up in because it is boring. it demonstrates that krebs views himself as similar to the other soldiers from his town. it reveals that krebs is jealous of those who were able to stay in town and avoid the war.