Question: who played the leading role in perfecting movable type for printing
[{'answer': 'Johannes Gutenberg', 'provenance': [{'wikipedia_id': '47300', 'title': 'Movable type', 'start_paragraph_id': 4, 'start_character': 13, 'end_paragraph_id': 4, 'end_character': 31, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '47300', 'title': 'Movable type', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 408, 'bleu_score': 0.9699161750394991, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14188382506992357308}, 'section': 'Section::::Abstract.'}]}]