Martin Sheen does good job in keeping up the flow of information. There is an optional closed caption option that is excellent for helping students answer questions. It is a very good video for teaching middle school science. It hits on tectonic plates, volcanoes and several other subjects. I have made a question set with some answers in a word bank. Students must follow along to get the points. If you are a teacher you can log into Discovery education and check out many excellent videos. You could even have the students log in themselves if your district is involved. I can have the students access a list of clips and questions. All classes can benefit from this video.