A simple explanation of how the rotation of the earth causes night and day.

Introduces the way in which the sun's relationship to the earth is responsible for seasonal changes.

Explains how and why a thunderstorm occurs and gives safety steps to follow when lightning is flashing.

Explains the processes by which a hamburger and other foods are used to make energy, strong bones, and solid muscles as they pass through the digestive system.

An introduction to the human skeletal system, explaining how the 206 bones of the skeleton join together, how they grow, how they help make blood, what happens when they break, and how they mend.

Explains how fossils are formed and what they tell us about the past.

"Explains how water flows from brooks, to streams, to rivers, over waterfalls, through canyons and dams, to eventually reach the ocean."--Title page verso.

"Discusses the importance of trees as sources of food, oxygen, and other essential things"--Provided by publisher.

Explains how people create too much waste and how waste is now recycled and put into landfills.

Even though Mount Everest measures 29,028 feet high, it may be growing about two inches a year. A mountain might be thousands of feet high, but it can still grow taller or shorter each year. Mountains are created when the huge plates that make up the earth's outer shell very slowly pull and push against one another. Read and find out about all the different kinds of mountains. The earth's continents rest on plates that move slowly across our planet's...