A. Leaching
B. Dredging
C. Open-pit mining
D. Subsurface mining
2 Answers
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Dredging.
http://www.european-dredging.eu/Reasons_for_Dredgi…
Leaching is also called heap leaching. It is done by pouring acid and other chemicals over broken up ore and catching the fluids that leach out of the pile. The fluids are then refined. It is most commonly applied to extract copper, gold, and silver from ore, but is used for other metals as well.
Source(s): geologist -
a
Source(s): i am guessing
