1. Elementary, middle, and high school students'; Of elementary, middle, and high school students
1. Elementary, middle, and high school students'; Of elementary, middle, and high school students
1. elementary, middle, and high school students
1. Middle and high school students.
1. Was a junior/high/high school student.
1. Elementary, middle, and high school students.
1. If one is a student—elementary, junior high, or high school; If students—elementary, junior high, or high school
1. If one is a student (elementary, junior high, or high school); For elementary, junior high, and high school students
1. If/when elementary, middle, and high school students…; If/when (someone) is an elementary, middle, and high school student…
1. Was a junior/high/high school student.
1. Was not a junior/senior/high school student.; Was not a student at those levels.