Question: who are the superheroes in age of ultron
[{'answer': 'Tony Stark / Iron Man', 'provenance': [{'wikipedia_id': '36484254', 'title': 'Avengers: Age of Ultron', 'start_paragraph_id': 12, 'start_character': 33, 'end_paragraph_id': 12, 'end_character': 53, 'bleu_score': 1.0, 'section': 'Section::::Cast.\n'}]}, {'answer': 'Thor', 'provenance': [{'wikipedia_id': '36484254', 'title': 'Avengers: Age of Ultron', 'start_paragraph_id': 5, 'start_character': 83, 'end_paragraph_id': 5, 'end_character': 87, 'bleu_score': 1.0, 'section': 'Section::::Plot.\n'}]}, {'answer': 'Bruce Banner / Hulk', 'provenance': [{'wikipedia_id': '36484254', 'title': 'Avengers: Age of Ultron', 'start_paragraph_id': 14, 'start_character': 28, 'end_paragraph_id': 14, 'end_character': 46, 'bleu_score': 1.0, 'section': 'Section::::Cast.\n'}]}, {'answer': 'Steve Rogers / Captain America', 'provenance': [{'wikipedia_id': '36484254', 'title': 'Avengers: Age of Ultron', 'start_paragraph_id': 15, 'start_character': 27, 'end_paragraph_id': 15, 'end_character': 56, 'bleu_score': 1.0, 'section': 'Section::::Cast.\n'}]}, {'answer': 'Natasha Romanoff / Black Widow', 'provenance': [{'wikipedia_id': '36484254', 'title': 'Avengers: Age of Ultron', 'start_paragraph_id': 16, 'start_character': 34, 'end_paragraph_id': 16, 'end_character': 63, 'bleu_score': 1.0, 'section': 'Section::::Cast.\n'}]}, {'answer': 'Clint Barton / Hawkeye', 'provenance': [{'wikipedia_id': '36484254', 'title': 'Avengers: Age of Ultron', 'start_paragraph_id': 17, 'start_character': 29, 'end_paragraph_id': 17, 'end_character': 50, 'bleu_score': 1.0, 'section': 'Section::::Cast.\n'}]}]