A digital solution for your classroom with features created with teachers and students in mind: - Perpetual license - 24 hour, 7 days a week access - No limit to the number of students accessing one title at a time - Provides a School to Home connection wherever internet is available - Easy to use - Ability to turn audio on and off - Words highlighted to match audio In graphic novel format, text and illustrations explain the force of gravity and how it keeps us on Earth.