RELATION OF FREQUENCY IN NORTHEAST POWER GIRD TO POWER FLOW IN TIE-LINE BETWEEN NORTHEAST AND NORTH CHINA POWER GRIDS是什么意思_RELATION OF FREQUENCY IN NORTHEAST POWER GIRD TO POWER FLOW IN TIE-LINE BETWEEN NORTHEAST AND NORTH CHINA POWER GRIDS在线翻译_英语_读音_用法_例句