Text and illustrations describe the simple machines of wheels and axles.

Text and illustrations describe screws, a simple machine.

Text and illustrations describe wedges, a simple machine.

"In this volume, readers learn the different reasons why we cry--whether it's dirt in the air or a really strong emotion. They also learn about the parts of the body that make crying possible. Vibrant photographs and illustrations help readers make sense of a potentially difficult science topic. Readers are sure to find this book both humorous and educational"--Provided by the publisher.

Explains how hedgehogs got their name even thought they are not hogs, and describes their closest relatives, where they live, their anatomy, including their remarkable quills, their enemies, their diet, their young, and hedgehogs as pets.

Millions of people have cats and dogs. Still, many people have pet allergies. While these allergies can often be treated by medicines or allergy shots, it���s tough to find out the cause of your sneezing is the beloved family pet! Readers learn the causes of pet allergies and the common reactions they cause. Colorful photographs of cute and cuddly pets accompany practical advice on living with pet allergies, including some ways to decrease reactions....

Simple text and photographs discuss how to choose and take care of a pet bunny.

"Velociraptor fossils were first discovered in 1923 and quickly became known as one of the fiercest--and feathered--predators of the prehistoric age. Only about 6 feet long as an adult, these amazing animals hunted in groups and used their brains to steal eggs and find other food. Readers will love learning what these creatures looked like with the help of colorful illustrations, and detailed text explains just how these dangerous dinosaurs lived...