I found this video on WatchKnowLearn.org It actually comes from YouTube and was produced by Geography Tutor.   The video investigates various types of land forms: mountains, plains, islands; and water forms: oceans, rivers, tides and much more. You can see pictures for each landform and listen to their definitions and how these landmasses were formed. The activity you have to do is to compare the list of geographical features we have seen in Unit 4 in our book and take note of the new ones we didn't see in the book.