Lesson 31 The sculptor speaks 雕塑家的语言 Lesson 32 Galileo reborn 伽利略的复生 Lesson 33 Education 教育 Lesson 34 Adolescence 青春期 Lesson 35 Space odyssey 太空探索 Lesson 36 The cost of government 政府的开支 Lesson 37 The process of ageing 衰老过程 Lesson 38 Water and the traveller 水和旅行者 Lesson 39 What every writer wants 作家之所需 Lesson 40 Waves 海浪 Lesson 41 Training elephants 训练大象 Lesson 42 Recording an earthquake 记录地震 Lesson 43 Are there strangers in space? 宇宙中有外星人吗？ Lesson 44 Patterns of culture 文化的模式 Lesson 45 Of men and galaxies 人和星系 Lesson 46 Hobbies 业余爱好 Lesson 47 The great escape 大逃亡 Lesson 48 Planning a share portfolio 规划股份投资