Unit One Big Bucks the Easy Way 1
Unit Two Deer and the Energy Cycle 17
Unit Three Why Do We Believe That the Earth Is Round? 32
Unit Four Jim Thorpe 46
Unit Five To Lie or Not to Lie-the Doctor's Dilemma 61
Unit Six How to Mark a Book 78
Unit Seven The Luncheon 98
Unit Eight The New Caves 119
Unit Nine Journey West 135
Unit Ten Why People Work 152