A staff member works at a private factory of environmental friendly materials of the Shiqiao industrial park in Yiyuan County of Zibo City, east China's Shandong Province, Nov. 3, 2018. Yiyuan County boosts the environmental friendly and innovative development of private enterprises in recent years.Over 4,000 private enterprises in the county have formed a number of industrial clusters and provided about 40,000 jobs for local people. (Xinhua/Zhao Dongshan)