Question: earth's magnetic field seems to reverse orientations about every
[{'answer': 'million years', 'provenance': [{'wikipedia_id': '2203131', 'title': 'Geomagnetic reversal', 'start_paragraph_id': 2, 'start_character': 94, 'end_paragraph_id': 2, 'end_character': 107, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2203131', 'title': 'Geomagnetic reversal', 'start_paragraph_id': 6, 'start_character': 0, 'end_paragraph_id': 6, 'end_character': 667, 'bleu_score': 0.9810405040225261, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16937293616102652990}, 'section': 'Section::::History.\n'}]}]