A taxi driver falls asleep in his waiting outside a natural gas station in Taiyuan, capital of north China's Shanxi Province, on the early morning of December 14, 2011.
Gas shortage, the rising number of oil-turned-gas cars as a result of high oil prices and a small number of gas stations in many cities all contributed to the long queues in Xi'an, Lanzhou, Haikou and other cities. [CNS Photo/Wei Liang]
