Top: File photo taken in 1983 by Yan Yang shows a worker cleaning sewer in Huangshi of central China's Hubei Province. Bottom: Photo taken on June 25, 2019 by Wang Kai shows a sanitation worker controlling an automatic device to clean sewer in Gaotang County of east China's Shandong Province. 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)