China has changed people's life with its high-speed rail. Chinese people didn't enjoy 1 . (them) for t r aveling tens of hours by train in the past, but their feelings have changed since they got the new high-speed trains. High-speed rail in China is 47. ( design) for speeds of 250-350km per 48. . Compared with ordinary trains, the high-speed rains are 49. (smart) and more energy-efficient,with more space inside. They are completely researched and developed50. Chinese people, High-speed rail is developing 51. (rapid)in China. Now China has the 52. ( long) high-speed rail network in the world. In recent years, China has successfully 53. (export) high-speed rail technology to many 54. (country). The Chinese are 55. ( pride) of China's high-speed rail.