Invention of 1,000 line switch with disc bank having ten concentric rows of line contacts. Not used commercially. Formation of Strowger Automatic Telephone Exchange.是什么意思_Invention of 1,000 line switch with disc bank having ten concentric rows of line contacts. Not used commercially. Formation of Strowger Automatic Telephone Exchange.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句