We are using Holt Science and Technology Earth Science this year and will go on to Physical Science next year. It's a regular public school textbook, so it's not super exciting, but it does cover all the bases. There are vocabulary words and comprehension questions at the end of each section, and a larger review at the end of each chapter. It gets the job done, which is what I need right now. While I would love to do more hands-on inquiry-based science with my kids, my focus now is more on the basic skills.