Walker, Sally M

Full-color photographs and simple text describes the mosquito, its body parts, and the spread of West Nile virus.

An introduction to the physical characteristics, habits, and natural environment of the common and the pygmy hippopotamus.

Describes the physical characteristics, habitats, diet, communication, and life cycle of rhinoceroses, and discusses the problem of rhino poaching.

Describes the behavior, habitat, and life cycle of dolphins.

Explains the concepts of work and friction; describes machines, wheels, and axles; and includes simple experiments.

Explains what wedges are and how they work and uses simple experiments to help students understand their applications in everyday life.

Explains the concept of work, describes machines and different types of screws and how they are used, and includes simple experiments.

Explains the concepts of work, gravity, and friction, describes machines and different kinds of pulleys, and includes simple experiments.

Tells the story of Dr. William Hammer and his crew, who, in 1991, discovered dinosaur bones in Antarctica.

An introduction to fossils, our window into the past.