Question: what is using plants to extract metals called
[{'answer': 'Phytoremediation', 'provenance': [{'wikipedia_id': '1068768', 'title': 'Phytoremediation', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 16, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1068768', 'title': 'Phytoremediation', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 382, 'bleu_score': 0.7514500083341361, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5564091774048240651}, 'section': 'Section::::Abstract.'}]}]