I wonder why zips have teeth and other questions about inventions
Part of the I wonder why series
This highly popular and long-running series has been revamped for a new generation of readers, with a clean, crisp redesign and colourful covers.
The series explores questions that young readers ask about the world around them in an unrivalled child-friendly style.
The conversational format is perfect for delivering solid information in a natural, amusing and imaginative way.