Hello guys, Welcome to Africa's Largest Video Search Engine, and you are watching TED 中英雙語字幕: David Christian 大歷史. and this video is uploaded by 雙語TED at 2015-05-03T02:42:56-07:00. We are just promoting this video only for entertainment and educational purpose only. I hop you like our Video Search Engine. [vz-V30ikAm0]