The Digital option of this all-new comprehensive teaching and learning program gives you access to all of the online student resources for the series available on Cambridge GO. Minimum system requirements You must be connected to the internet to activate your account and download the PDF Textbook and additional online resources. The PDF Textbook is designed for full functionality using the latest version of Adobe Reader. The markup function is available in selected PDF readers for the iPad and other devices using iOS. Check your PDF reader specifications. At the time of printing Good Reader and PDF Expert were viable options. Help at [email protected].