What do Pulleys and Gears do? (Paperback) (What Do... Do?)
By David Glover.
Description
Part of a series which aims to develop children's knowledge of the basic principles of design and technology. Each book introduces a particular principle and explores how it is used in different gadgets and machines. This book looks at pulleys and gears. - from Amzon
ISBN(s)
0431062722, 9780431062723
