double-track railroad

• 双轨铁路

double-track railroad的用法和样例：

例句

1. A single track system in 1910,it was completely electrified and double-tracked by 1983.
   它在一九一零年投入服务时是一个单轨系统，在一九八三年，已改善成为一个完全电气化的双轨铁路系统。