Take an underground copper mine as studying object, on which the surface has to be protected, the mining method of sublevel filling method with roof reconstructing is studied.

以某地下铜矿为研究对象，研究了地表要求保护的前提下极破碎矿体的顶板再造上向分段充填采矿法。

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It spreads primarily by underground stems; colonies form when pieces of the root system or whole plants float into an area and take root or when seeds float into a suitable area and germinate.

它主要通过地下茎传播；当根系统碎片或整个植物漂浮到一个区域并生根，或当种子漂浮到一个合适的区域并发芽时，菌落就形成了。

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The Underground station at Liverpool Street was closed because of overcrowding. Revellers unable to take the train staged an impromptu party on the concourse instead.

利物浦街的地铁站因为过分拥挤，被关闭。狂欢者无法坐火车，转而在中央大厅上演了即席晚会。

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Take an Underground train a few stops from the borough of Westminster, and life expectancy drops by 12 years.

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For example, take Advanced Underground Construction, an Iowa-based company, and its principal, William David Ward II.

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There's been a longstanding rumor that Google liked ASUS' Eee Pad MeMO ME370T well enough to bestow it with an official Nexus badge and take it underground until it was ready to show its Jelly Bean face.

ENGADGET: Google Nexus tablet reportedly shows its pre-rendered face, packing Android 4.1 and a $199 price