Discover just how important the movement of people to and across the United States has been throughout the nations history. Helpful photographs, fact boxes, and a timeline bring all the aspects of imm
Discusses how viruses and bacteria are spread, describes why some people get motion sickness, and examines the common emissions from transportation and the effects on air pollution.
Explains the characteristics of platinum, where it is found, the rarity of the metal, how it is mined, and some of its uses, including jewelry, dental implants, and electronics.
Examines the causes of earthquakes, how they are predicted and can be prepared for, and examples of historic quakes in San Francisco, Haiti, and Japan.
Describes the various parts of the skeleton and how bones grow, and discusses joints, the difference between male and female skeletons, bone injuries and diseases, and related topics.
Introduces the black widow spider, describing its physical characteristics, habitat, and the venom that its produces to kill prey and scare away predators.
