Book excerpt: Endorsed by WJEC and written by experienced examiners David Burtenshaw and Sue Warn, this WJEC A2 Geography Student Unit Guide is the essential study companion for Unit G4: Sustainability.This full-colour book includes all you need to know to prepare for your unit exam: clear guidance on the content of the unit, with topic summaries, knowledge check questions and a quick-reference index exam advice throughout, so you will know what to expect in the exam and will be able to demonstrate the skills required exam-style questions, with graded student responses, so you can see clearly what is required to get a better grade