The world fastest man is marching on. Jamaican sprinter Usain Bolt returned to competition at the 2012 London Games today, fresh off his victory in Sunday's 100-meter finals. Bolt advanced to the semifinals of the men's 200-meter sprint, along with teammate Yohan Blake, the 100-meter silver medalist. Today brought disappointment for Chinese hurdler Liu Xiang. The 2004 gold medalist in 110-meter hurdles hit the first hurdle in his opening round race, crashed onto the track and had to be carried off. One of his fans expressed sorrow.世界飞人大战正在进行.周日刚刚斩获男子100米金牌的牙买加短跑名将博尔特今日重回2012伦敦奥运会赛场.博尔特携手队友布雷克--100米银牌得主,挺进男子200米半决赛.对于中国跨栏选手刘翔来说,今天是失落的一天.这位04年金牌选手在110米栏首场比赛中撞上第一个栏,随后倒地,最终离场.一名粉丝向记者表达了他的伤悲. "I think everyone feels sorry about him. I feel sorry about him, because, you know, the opportunity for London 2012 is like, is a very great opportunity, but, you know, Liu Xiang is now 29-years-old.""我想每个人都会为他感到伤心.我为他感到惋惜,因为2012年伦敦奥运会对他来说是一个机会,你也知道,他已经29岁了." ________________________________________.