Use a Pulley: Simple Machines?Pulleys. Questo articolo non è disponibile.Use a Pulley: Simple Machines?Pulleys

Grandfather gave some jobs to a lazy boy. The clever boy came up with ideas to make the jobs easier. Let's find out how the boy used pulleys. Simple presentations of key introductory science principles make this series ideal for emergent readers. Each book includes questions and an activity to encourage learning, engagement and independent thinking.