operating pit造句

Mining commenced in 1996 and now extends over three individual operating pits : Plumtree, Wallanbah and Broadmeadows.
Energy Resources of Australia Ltd ( ERA ) was named Explorer of the Year at the sixth annual Australian Mining Prospect Awards held in Sydney on Wednesday 11 November 2009 . During 2008, ERA's exploration programme identified a very significant mineral resource adjacent to the existing Ranger 3 operating pit.
It's difficult to find operating pit in a sentence. 用operating pit造句挺难的