History﹕Salty power

【明報專訊】We all know that mankind can't live without air, food or water. The same is true for salt. Salt is a key to the mystery of our planet and the cosmos (宇宙). Big History reveals how this simple molecule underpins (支撐) our civilisation, launches wars and builds monuments (古蹟) like the Great Wall of China. Humans just can't survive without salt.