The following excerpt is from a persuasive essay. What is it an example of? Like any other facility, keeping a school open requires a great deal of money. When a school changes to a year-round schedule, the costs skyrocket. Keeping school open in the middle of summer requires air conditioning, and that adds significantly to the school’s expenses. "Student Model: Summer: 15 Days or 2 1/2 Months?" Thoughtful Learning, 7, Aug. 2015, https://k12.thoughtfullearning.com/studentmodels/summer-15-days-or-2-12-months.