ozonea form of oxygen that shields the Earth from harmful ultraviolet radiationThe depletion of the ozone layer was caused primarily by chlorofluorocarbon chemicals.NoteThe depletion of the ozone layer was caused primarily by chlorofluorocarbon chemicals.Elon.io is an online learning platformWe have an entire course teaching TOEFL Academic Vocabulary grammar and vocabulary.Start learning TOEFL Academic Vocabulary now