National Geographic theme sets

An introduction to tornadoes with information on how they begin, when and where they occur, the damage they can do, and some of the worst storms of this century.

Describes floods and how meteorologists use cloud movement, tools, and technology to predict the weather.

Describes the different types of muscle cells and what the muscle cells in our bodies do.

The invention of the cotton gin revolutionized the difficult and time-consuming work of cleaning cotton. Many people became wealthy from the production of cotton, but it also led to an increase in slavery. The invention of the cotton gin led to other inventions such as the cotton picker.

"The ocean region of Greenland provides many natural resources that people use.

"The mountains of Peru provide many natural resources that people use.

"The tropical rain forests of Indonesia provide many natural resources that people use".