Lesson 25 Non-auditory effects of noise 噪音的非听觉效应 First listen and the…

Lesson 24 Beatuy 美 First listen and then answer the following question. 听录音…

Lesson 23 Bird flight 鸟的飞行方法 First listen and then answer the following q…

Lesson 22 Knowledge and progress 知识和进步 First listen and then answer the fo…

Lesson 21 William S. Hart and the early 'Western' film 威廉.S. 哈特和早期限的‘…

Lesson 20 Snake poison 蛇毒 First listen and then answer the following question…

Lesson 19 The stuff of dreams 话说梦的本质 First listen and then answer the f…

Lesson 18 Porpoises 海豚 First listen and then answer the following question.…

Lesson 17 A man-made disease 人为的疾病 First listen and then answer the foll…

Lesson 16 The modern city 现代城市 First listen and then answer the following q…

Lesson 15 Secrecy in industry 工业中的秘密 First listen and then answer the fol…

Lesson 14 The Butterfly Effect 蝴蝶效应 First listen and then answer the follow…

Lesson 13 The search for oil 探寻石油 First listen and then answer the followin…

Lesson 12 Banks and their customers 银行和顾客 First listen and then answer the…

Lesson 11 How to grow old 如何安度晚年 First listen and then answer the followi…

Lesson 10 Silicon valley 硅谷 First listen and then answer the following questi…

Lesson 9 Royal espionage 王室谍报活动 First listen and then answer the followin…

Lesson 8 Trading standards 贸易标准 First listen and then answer the following …

Lesson 7 Bats 蝙蝠 First listen and then answer the following question. 听录音，…

Lesson 6 The sporting spirit 体育的精神 First listen and then answer the follow…