短語詞組短語automatic telephone switching system 自動電話交換系統(tǒng);自動manual telephone switching system 人工電話交換機Public Telephone Switching System 交換機mobile telephone switching system 移動電話交換機toll telephone switching system 長途電話交換機;長話交換機local telephone switching system 市內(nèi)電話交換機;地區(qū)電話交換機STEP TELEPHONE SWITCHING SYSTEM 步進制電話交換機SOHO TELEPHONE SWITCHING SYSTEM 求電話交換機 返回 telephone switching system