What was different about the vietnam war compared to the united states previous wars?

Why does black lung aka arthur morgan let only jhon and abigail go and not sadie in the last chapter

How do i can change this sentence : a modern physician in a small town not only is proficient in general medicine but surgery as well. to parallel structure?

The difference between the present reservoir, with its silent sterile shores and debris-choked side canyons, and the original glen canyon, is the difference between death and life. glen canyon was alive. lake powell is a graveyard. which word best contributes to the author’s sad tone?