On Necessity and Feasibility of Extending Coverage by Prefectural Radio Stations in Mountainous Areas in Western Provinces Using Sky Ware of High-Power Medium Wave是什么意思_On Necessity and Feasibility of Extending Coverage by Prefectural Radio Stations in Mountainous Areas in Western Provinces Using Sky Ware of High-Power Medium Wave在线翻译_英语_读音_用法_例句