China has opened the world’s longest cross-sea bridge – which stretches five miles further than the distance between Dover and Calais.The Jiaozhou Bay bridge is 26.4 miles long and links China’s eastern port city of Qingdao to the offshore island Huangdao.The road bridge, which is 110ft wide and is the longest of its kind, cost nearly £1billion to build.That structure features two bridges running side by side and is 23.87 miles long.The three-way Qingdao Haiwan bridge is 174 times longer than London’s Tower Bridge, spanning the River Thames, but cuts only 19 miles off the drive from Qingdao to Huangdao.Two separate groups of workers have been building it from different ends of the structure since 2006.After linking the two ends of the bridge on December 22, one engineer said: ‘The computer models and calculations are all very well but you can’t relax until the two sides are bolted together. -