How Do You Measure Time?

Who were the earliest Americans? When, how, and from where did they enter and spread across the continent? And what is their relationship to modern Native Americans? Anthropologists develop theories to answer these questions based on the evidence they discover. Their theories—and the discoveries that prove and disprove them—are highlighted in this fascinating volume, full of awe-inspiring facts and incredible breakthroughs. Readers will feel like anthropologists and archaeologists themselves as they read about bones and artifacts, and what they reveal about the ancient cultures that roamed...

Basic concepts about electricity. Topics include: CA circuits, Serial and parallel circuits, transformers, power distribution and circuit repairs. With questionnaire. Ideal for high-school and college.

Lincoln Rhyme and Amelia Sachs return to face a criminal whose ingenious staging of crimes is enabled by a terrifying access to information. When Lincoln's estranged cousin is arrested on murder charges, the case is closed. Forensic evidence from Arthur's home is found all over the scene of the crime, and it looks like the fate of Lincoln's relative is sealed.

Explains, in simple terms, the reasons for skin color, how it is determined by heredity, and how various environmental factors affect it.