Conrad, David

Text and photos present information about the past and future of space exploration.

An introduction to gravity that defines what it is, discusses the study of it, describes what the effects of more or less gravity on Earth would be, and includes a related activity.

Brief text describes how some of the unpleasant things the body produces, like gas, ear wax, pus, and sweat, are important aids to staying healthy.

An introduction to gravity that defines what it is, discusses the study of it, describes what the effects of more or less gravity on Earth would be, and includes a related activity.

Photographs and text provide a simple introduction to astronomy and space exploration.

Color photos and simple text describe body functions, explaining the causes and the purposes of gas, ear wax, mucus, scabs, scars, sweat, and bad breath.

Explains how gravity works and how it was discovered, and includes two simple gravity experiments.

Photographs and text describe the weather and how it is studied.

Briefly introduces a wide variety of occupations.

Profiles Wilma Rudolph, who overcame polio to become a runner, the first American woman to win three Olympic gold medals, and the founder of a group that helps poor children to do better in school and learn sports.