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The Epic Interactive Encyclopedia 1997
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The_Epic_Interactive_Encyclopedia_97.iso
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1992-09-03
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511b
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14 lines
A tunnel is a passageway through a mountain,
under a body of water, or under ground.
Tunnelling is a significant branch of civil
engineering in both mining and transport. In
the 19th century there were two major
advances: the use of compressed air within
underwater tunnels to balance the external
pressure of water, and the development of the
tunnel shield to support the face and assist
excavation. The CHANNEL_TUNNEL which has now
been completed, links England With France.
Subject by: Vince Pike