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The Tunnel Challenge
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Tunnel Shield Through Mountain
Your tunnel shield just conked out!

Tunnel shield _+_ Hard Rock __ Wrong
Learn more       Tunnel Score: 0

Tunnel shields are built to slice through soft soil, like sand, clay, and silt. They're not strong enough to carve through a mountain of rock. In order to bore into this mountain, you need a machine with teeth strong enough to split rock. Besides, tunnel shields are used to support soft soil -- these dense mountain walls can support themselves! Try again!


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