underground system

基本解释

Visit our ticket office and buy one of the travel cards that permit you to travel all over the underground system.
请光临我们的售票处，选择购买一张允许你乘坐伦敦地铁系统所有地铁线的乘车卡。
Beijing's east-west metro line used to terminate at Xidan. Its long-awaited eastward extension in the summer of 2002 was accompanied by numerous changes in the Beijing underground system.
北京东西线地铁以前的终点站是西单，2002年夏季期待已久的向东延伸带来了地铁系统的很多变化。
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London – the oldest. The first line was thepartially underground Metropolitan Railway Line which opened in 1863, and isnow a part of the more expansive London Underground system.
最古老的地铁——伦敦地铁。开通于1863年的伦敦市地下铁路是伦敦地铁的前身。这一段开通于那个年代的地铁已经成为了正在日益扩张的伦敦地铁系统的一部分。

London may be famous for its red double-decker buses, but it is the underground system, parts of it more than a hundred years old, that is especially vulnerable.
What we don't get here is a sense of whether there really is an alternate secret postal system that serves a sort of underground of private networks.
在这里我们所不明白的是，是否真的存在一个,提供地下的,私密的通信服务的，秘密邮政系统。
耶鲁公开课 - 1945年后的美国小说课程节选
His idea started when he heard two religious workers playing music for free in New York City's underground transportation system.

Mr Prescott says that much larger sums are needed to provide London with an underground system fit for the 21st century.
ECONOMIST: London Underground