Question: when did humans start keeping track of time
[{'answer': 'about 3500 BC', 'provenance': [{'wikipedia_id': '14449116', 'title': 'History of timekeeping devices', 'start_paragraph_id': 11, 'start_character': 295, 'end_paragraph_id': 11, 'end_character': 308, 'bleu_score': 1.0, 'section': 'Section::::Timekeeping devices of early civilizations.:Ancient Egypt.\n'}]}, {'provenance': [{'wikipedia_id': '14449116', 'title': 'History of timekeeping devices', 'start_paragraph_id': 11, 'start_character': 0, 'end_paragraph_id': 11, 'end_character': 351, 'bleu_score': 0.96746874041754, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5222512147909213994}, 'section': 'Section::::Timekeeping devices of early civilizations.:Ancient Egypt.\n'}]}]