A worker checks the data of newly installed natural gas equipment

A worker of Dongyuan Heat Supply Company in Zhangjiakou City, Hebei Province, checks the data of newly installed natural gas equipment, November 9, 2017. To widen the use of clean heat supply and improve the winter air quality, Hebei Province plans to replace coal with natural gas or electricity for heating purposes in 1,964,000 households this year. (Xinhua/Wang Xiao)