Chapter 01 The Origin of the Universe 宇宙起源 Lesson 01 Pangu Created the Universe 盘古开天地 ... 002 Lesson 02 A Planet that We Can Trust 一个值得我们信赖的星球 ... 017 Lesson 03 Recycle 1 形容词的比较级与*** ... 025 Chapter 02 The Origin of Humans 人类起源 Lesson 04 Nvwa Created Humans 女娲造人 ... 038 Lesson 05 From Fish to Human 从鱼到人 ... 053 Lesson 06 Recycle 2 一般过去时 ... 061 Chapter 03 The Courage to Explore the Unknown 探索未知的勇气 Lesson 07 Kuafu Chased the Sun 夸父逐日 ... 078 Lesson 08 Solar Energy 太阳能 ... 093 Lesson 09 Recycle 3 一般现在时 ... 101 Chapter 04 The Relationship Between Humans and Nature 人与自然的关系 Lesson 10 Nvwa Mended the Sky 女娲补天 ... 118 Lesson 11 A Letter from Mother Earth 来自地球妈妈的一封信 ... 133 Lesson 12 Recycle 4 There be句型的时态/量 ... 142 Chapter 05 The Power of Fire 火的力量 Lesson 13 Drill Wood to Make Fire 钻木取火 ... 162 Lesson 14 Fire Safety 消防** ... 177 Lesson 15 Recycle 5 定语从句 ... 186 Chapter 06 The Secrets of Plants 植物的秘密 Lesson 16 Shennong Tasted Hundreds of Plants 神农尝百草 ... 198 Lesson 17 Can Music Help Plants to Grow? 音乐能帮助植物生长吗? ... 213 Lesson 18 Recycle 6 情态动词表推测 ... 223