Question: where is cast iron used on a car
[{'answer': 'cylinder heads', 'provenance': [{'wikipedia_id': '132784', 'title': 'Cast iron', 'start_paragraph_id': 3, 'start_character': 355, 'end_paragraph_id': 3, 'end_character': 369, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'cylinder blocks', 'provenance': [{'wikipedia_id': '132784', 'title': 'Cast iron', 'start_paragraph_id': 3, 'start_character': 389, 'end_paragraph_id': 3, 'end_character': 404, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'gearbox cases', 'provenance': [{'wikipedia_id': '132784', 'title': 'Cast iron', 'start_paragraph_id': 3, 'start_character': 409, 'end_paragraph_id': 3, 'end_character': 422, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '132784', 'title': 'Cast iron', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 504, 'bleu_score': 0.952004915197278, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11476030248670311402}, 'section': 'Section::::Abstract.'}]}]