Question: what are the three main cereal crops in the world
[{'answer': 'Maize ( corn )'}, {'answer': 'Rice', 'provenance': [{'wikipedia_id': '6700', 'title': 'Cereal', 'start_paragraph_id': 15, 'start_character': 122, 'end_paragraph_id': 15, 'end_character': 126, 'bleu_score': 1.0, 'section': 'Section::::Farming.:Planting.\n'}]}, {'answer': 'Wheat', 'provenance': [{'wikipedia_id': '6700', 'title': 'Cereal', 'start_paragraph_id': 12, 'start_character': 175, 'end_paragraph_id': 12, 'end_character': 180, 'bleu_score': 1.0, 'section': 'Section::::Farming.\n'}]}]