Question: where does fossil fuel natural gas come from
[{'answer': 'deep underground rock formations', 'provenance': [{'wikipedia_id': '22131', 'title': 'Natural gas', 'start_paragraph_id': 4, 'start_character': 24, 'end_paragraph_id': 4, 'end_character': 56, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'coal beds', 'provenance': [{'wikipedia_id': '22131', 'title': 'Natural gas', 'start_paragraph_id': 4, 'start_character': 108, 'end_paragraph_id': 4, 'end_character': 117, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '22131', 'title': 'Natural gas', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 540, 'bleu_score': 0.9757530668325981, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7413412971510924179}, 'section': 'Section::::Abstract.'}]}]