A worker welds a cart back together in one of the railway tunnels under construction in central Beijing January 10, 2008. Three new subway lines are scheduled to be in operation by the end of July as part of the preparations for the Beijing Olympics, with organisers leaving nothing to chance for China's "coming-out party" this year ahead of the opening ceremony on August 8. The last Olympics in Athens were beset by last-minute construction problems, but with seven months to go before the start, the city is primed for the world's biggest sporting event. [Agencies]