What happens when-- ?

Photos and text answer questions about the wind and its effects on the earth.

An introduction to communication, explaining how sound is made, how people learn by talking and asking questions, and how people rely on communication skills in their everyday lives.

Describes how the parts of the body work together to produce speech.

Describes how the body sends messages to the brain registering touch and sensation.

Describes how the brain works and how this complex and powerful organ interacts with other parts of the body to receive and transmit messages.

Discusses the discovery and evolution of the wheel and its many different uses.

Discusses rain and related topics such as rainbows, snow, clouds, floods, and water power.

An introduction to volcanoes including sections on how they form, why they erupt, and how they affect the surrounding land.

An introduction to cooking including sections on baking, preserves and types of food.

An introduction to fires including sections on how they start, how to prevent them and their after-effects.