註釋
I Wonder Why Planes Have Wings is the perfect introduction to transportation, featuring SpaceShipTwo, hovering planes, supersonic cars and much more.
What do you want to find out? Clear, lively text answers all those tricky questions about how the world works, while friendly, funny cartoons add interest.
Colourful, surprising and full of information, the I Wonder Why series will set young minds buzzing. Each book comes with a free downloadable audio book to enjoy on the go.