Unit 1 Chronology：Talking about When Things Happen
Chapter 1 Napoleon：FrOm Schoolboy to Emperor
Chapter 2 Pompeii：Destroyed，F(xiàn)orgotten，and Found
Chapter 3 Steve Jobs：A Man with a Vision
Video Surviving an Avalanche

Unit 2 Process：Describing How Things Work
Chapter 4 Roller Coasters：The Ups and Downs of How They Work
Chapter 5 Language：How Children Acquire Theirs
Chapter 6 Robots：How They Work and Learn to Work
Video Tristan da Cunha Oil Spill

Unit 3 Classification：Defining and Putting Things into Categories
Chapter 7 A TidaI Wave：What Is It？Can We Predict lt？
Chapter 8 Levels of Language：Formal and Informal
Chapter 9 Power：The Kinds of Power People Use and Abuse
Video People， Plants，and Pollinators

Unit 4 Comparison and Contrast：Describing Similarities and Differences
Chapter 10 Asian and African Elephants：Similarities and Differences
Chapter 11 Lincoln and Kennedy：Different Times．Similar Destinies
Chapter 12 The Titanic and the Costa Concordia：Tragedies at Sea
Video Free Soloing with Alex Honnold

Unit 5 Cause and Effect：Describing the Reason Things Happen
Chapter 13 Dinosaurs：Why They Disappeared
Chapter 14 The U．S．Civil War：Why It Happened
Chapter 15 Endangered Species：Why Are They Endangered？
Video The Surma People

Credits