High-speed train G90 leaves Zhengzhou, capital of central China's Henan Province, for Beijing, capital of China, Dec. 26, 2012. Zhengzhou is one of the 35 stops of the 2,298-kilometer Beijing-Guangzhou High-speed Railway, the world's longest, which was put into operation on Wednesday. Running at an average speed of 300 kilometers per hour, the high-speed railway will cut the travel time to about 8 hours from the current 20-odd hours by traditional lines between the country's capital and capital of south China's Guangdong Province. [Xinhua photo]