Left: File photo taken in the 1970s and provided by Nanchang railway administration shows railway worker Chen Shenglun examining the conditions of a locomotive with a hammer in Nanchang, east China's Jiangxi Province. Right: Photo taken on May 31, 2019 by Chen Fei shows technicians controlling a detective robot to examine a bullet train in east China's Shanghai. In 1949 when the People's Republic of China was founded, the Chinese people faced a devastated country that needed to be rebuilt from scratch after decades of warfare and chaos. After decades of unremitting endeavors and dedication by the Chinese people, China has grown to be the world's second largest economy. In 1952, China's GDP was 30 billion U.S. dollars, while in 2018, its GDP reached 13.61 trillion U.S. dollars, an increase of 452.6 times. A group of combo photos give you a glimpse of what Chinese people did decades ago and what they do right now. Undoubtedly, people from all walks of life in China with hard work and wisdom have made contributions to the country's development. (Xinhua)