It is already being used in the 1.8km 8.448 Mb/s PCM-120 route optic fibre telephone communication system.是什么意思_It is already being used in the 1.8km 8.448 Mb/s PCM-120 route optic fibre telephone communication system.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句