01 Amazing Flowers 02 Cactus in the Desert 03 The Migration of Birds 04 Fruits and Vegetables 05 Review (Lessons 1− 4) 06 How Plants Get Water 07 Dandelions 08 Fossils. 09 Where to Find Fossils 10 Review (Lessons 6−9) 11 How Old Are Fossils? 12 The Air We Breathe 13 Fizzy Soda 14 Wind 15 Review (Lessons 11−14) 16 How Do Birds Fly? 17 The Heat of the Sun 18 Refracting Light 19 Movie Projectors 20 Review (Lessons 16−19). 21 Adapting to Survive 22 Competing for Resources. 23 Weather Forecasts 24 World Climates 25 Review (Lessons 21−24). 26 Life on the Tundra 27 Mirrors 28 Location 29 Energy and Motion 30 Review (Lessons 26−29) 31 Lightning. 32 Sound. 33 Minerals 34 Igneous Rocks 35 Review (Lessons 31−34) 36 El Nino. 37 Batteries 38 Caves 39 Elements and Atoms. 40 Review (Lessons 36−39) 41 Mercury. 42 The Common Raven 43 The Piranha 44 The American Alligator 45 Review (Lessons 41−44) 46 Meteors and Meteorites 47 The Cheetah 48 The Great White Shark 49 The Red Panda 50 Review (Lessons 46−49)