Question: what is the worst oil spill in history
[{'answer': 'Kuwaiti Oil Fires', 'provenance': [{'wikipedia_id': '158705', 'title': 'Oil spill', 'start_paragraph_id': 9, 'start_character': 54, 'end_paragraph_id': 9, 'end_character': 71, 'bleu_score': 1.0, 'section': 'Section::::Human impact.\n'}]}]