lǎo / shì / chéng / kòng / jiāo / huàn / jī / yǐ / jīng / zhú / jiàn / bèi / guāng / xiān / tōng / xìn / shè / bèi / qǔ / dài

老式程控交换机已经逐渐被光纤通信设备取代。

Older stored-program control exchanges have gradually been replaced by fiber-optic communication equipment.