Question: what is the method used to dig the metal ore from the ground called
[{'answer': 'Mining', 'provenance': [{'wikipedia_id': '20381', 'title': 'Mining', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 6, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '20381', 'title': 'Mining', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 243, 'bleu_score': 0.818704313669086, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13054694710489602377}, 'section': 'Section::::Abstract.'}]}]