Do all of these elements belong to the set of items students use in a classroom?
So each of these elements belong to a set. And this set, we are wondering if all of the items are used in a classroom by a student. These elements include a book, a pen, a ruler, a pencil, and a key. So to write all of these elements in one set, we list them all inside of braces, so book, pen, ruler, pencil, and key.
So the question is, do all of these elements belong to the set of items students use in a classroom? So do students use a book, pen, ruler, pencil, and key when they’re in a classroom?
Students usually use books, pens, rulers, pencils. However, there’ll be no need for a key, at least to use in the classroom. Maybe there will be a key for a lock on their locker or a key that a teacher may use to get into the classroom. But students in general would not use a key. So our final answer will be no.