Which rule should you follow to form possessive nouns

Which three parts of these excerpts reflect the idea that war affects not only the minds of the combatants but also their physical reactions?

Which excerpt from "hills like white elephants" provides the most details about the main characters' lives outside the railway station? click here to read an excerpt.

How are the two arguments made in the passages different? a. the first passage claims that pets in class will children with health problems; the second passage says pets will make some health problems worse. b. the first passage claims that students’ nervousness will decrease around pets; the second says that students’ nervousness will increase around pets. c. the first passage claims that pets will make the teacher’s work easier by keeping students busy; the second passage says pets will make the teacher’s work harder. d. the first passage claims that pets in school will be good for kids’ mental health; the second passage says pets will be bad for kids’ mental health.