An estimated half a million mice live in the Underground system so that should keep them both busy for a while.

地铁中居住着约50万只老鼠，这够姊妹两忙上一阵子的了。

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In order to identify out the existence of the system and its structure, the geophysical electromagnetic technique is applied to detect and position the underground system.

为了查清该地下灌排系统的存在及其构造，采用地球物理电磁法进行了探测。

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The city planner decided to build an underground drainage system.

城市规划师决定建一个地下排水系统。

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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.

VOA: standard.2010.04.01

"These difficult to reach populations frequently go underground and remain not visible to the medical delivery system,"

VOA: standard.2009.11.15

looked at things like where should they locate waste water treatment facilities because of the impacts of climate change, what risks are likely to occur to their subway system because it's underground and already requires enormous pumping of water during certain large rainfall events."

VOA: standard.2010.06.14

London Stansted airport is a 45-minute journey from the capital and getting to London Heathrow by the underground system can take 50 minutes from parts of the city.

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The London Underground, known as the Tube, opened in 1863, making it the oldest underground system in the world, and this year, a series of celebrations are planned for its 150th anniversary.

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That made her part of the underground lending system, a general term that encompasses informal lending networks, private investors, loan sharks and others.

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