"Do You Know?" by Ladybird is a reading series based on STEM, suitable for children aged 5+ who are learning English as a foreign or second language. These non-fiction books at various levels feature videos, projects, and critical thinking activities. Each book poses big questions on STEM topics, from nocturnal animals to building bridges, developing children's language, communication, and research skills. The five levels progress from CEFR Pre-A1 to A2. "Pets," a starter reader, is Pre-A1 according to the CEFR and supports the YLE Starters exams. Long phrases introduce simple sentences and questions, as well as basic vocabulary. What is a pet? How good is a dog's nose? What jobs do cats do? Discover more about meowing, barking, and sled-pulling.