China’s Liu Xiang waves to the audience after winning a silver medal at the IAAF World Championships in Athletics in Helsinki, Finland, on August 12, 2005. The greatest track and field athlete of China announced his retirement on Sina Weibo, China’s version of Twitter, yesterday, with the injury-plagued Athens 2004 gold medal winner saying he had “no choice” but to bring down the curtain on his trail-blazing career. (More on P7)Xinhua