Get the most out of your CGP Grade 9-1 AQA Combined Science Higher Level Knowledge Organiser (9781789084924) with the matching Knowledge Retriever! It's really simple to use: once you've learnt a topic from the Knowledge Organiser, look it up in this Knowledge Retriever and test your memory by filling in as much info as you can. To make sure you know everything off by heart, and to check the bits you're finding trickier we've included a second tougher test to have a go at. Once you think you know your stuff, try the mixed practice quizzes to really put your understanding to the test!