Question: when did the chinese first use gunpowder as a weapon
[{'answer': '904', 'provenance': [{'wikipedia_id': '12063194', 'title': 'History of gunpowder', 'start_paragraph_id': 11, 'start_character': 377, 'end_paragraph_id': 11, 'end_character': 380, 'bleu_score': 1.0, 'section': 'Section::::Chinese beginnings.:Fire arrows.\n'}]}, {'provenance': [{'wikipedia_id': '12063194', 'title': 'History of gunpowder', 'start_paragraph_id': 11, 'start_character': 0, 'end_paragraph_id': 11, 'end_character': 1164, 'bleu_score': 0.9533086364313991, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17014390977585098864}, 'section': 'Section::::Chinese beginnings.:Fire arrows.\n'}]}]