Question: what is the name of the largest asteroid it is approximately 1000 km in diameter
[{'answer': 'Ceres', 'provenance': [{'wikipedia_id': '791', 'title': 'Asteroid', 'start_paragraph_id': 2, 'start_character': 791, 'end_paragraph_id': 2, 'end_character': 796, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]