To improve the energy mix,clean energy resource replaced coal as the fuel for 1902 coal-fired boilers in the urban and suburb areas of Beijing. A total of 1.28 billion cubic meters of natural gas was used,up by 33.7 percent over the previous year.是什么意思_To improve the energy mix,clean energy resource replaced coal as the fuel for 1902 coal-fired boilers in the urban and suburb areas of Beijing. A total of 1.28 billion cubic meters of natural gas was used,up by 33.7 percent over the previous year.在线翻译_英语_读音_用法_例句