Explains what tornadoes are, what causes them, and where and when they occur; discusses what happens during a tornado and who helps afterwards; and considers whether tornadoes can be predicted. Includes case studies.

"From the assassination of Archduke Franz Ferdinand to the Treaty of Versailles, this book gives an overview of the war. The causes of the war are discussed, as well as key battles on land, air, and sea."

Find out how machines can change a small force into a large force. What happens when forces are balanced? Why do moving things slow down? What are the benefits of friction? Includes three simple activities or experiments to try.

Find out about the organs, tissues, and cells that make up your body, and what your body needs to keep it working properly. Includes three simple activities or experiments to try.

"The trenches of Western Europe saw some of the heaviest fighting in World War I. Find out what life was like in the trenches as well as above ground for the soldiers who served there."--Amazon.com.

"World War I brought many changes for women. Some stepped into roles left vacant by men now serving overseas, while others helped the war effort as nurses, telephone operators, and more. This book explores the wartime roles of women around the world."--Amazon.com.