How do animals move? What flies fast? Find out all about quick cats, slow penguins and slithering snakes. Do You Know? is a series of levelled non-fiction books featuring video content, project work and critical-thinking activities to motivate and engage young learners. Covering a range of STEM topics from nocturnal animals to climate change, Do You Know? takes an enquiry-based approach, developing children’s language, communication and investigation skills. Recommended for children aged 7+, there are four levels progressing from CEFR level Pre-A1 to level A2. Each reader is accompanied by online video content, audio, video and comprehension activities, and suggestions for project work. Fast and Slow, a Level 4 Reader, is A2 in the CEFR framework and supports YLE Flyers exams. The longer text is made up of sentences with up to three clauses, more complex past and future tense structures, modal verbs and a wider variety of conjunctions.