Ages 9-12. This "encyclopedia for children aged 9+ covers all their favorite topics in a friendly, easy-to-read Q&A format, [meant] to dip into and browse. Find the answers to big questions like 'How do airplanes fly?,' 'Why do tigers have stripes?,' 'What's inside a black hole?,' and much more. Alongside the children's questions and the expert answers are ... Illustrations, photographs, and diagrams that bring every topic to life in rich detail and with ... Clarity 256 pages hc