Here’s a worksheet on the Greek word root hetero. It means, of course, different and other. The adjective heterogenous, used fairly regularly in certain domains of educated discourse, springs from this root, as to a number of English words, as the document will show you and your students.
If you find typos in this document, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.