More How Do They Do That?

Have you ever wondered:

- How do they know how much an aircraft carrier weighs?

- How do they get music onto a CD?

- How does an electric eel generate electricity?

- How do they know how long a second is?

- How do penguins stay warm in Antarctica?

- How do they teach guide dogs to cross at a green light?

The answers to these and many other everyday wonders are explained.

Here, in simple and easy-to-unders...