Question: who was the roman emperor when jerusalem was destroyed
[{'answer': 'Titus', 'provenance': [{'wikipedia_id': '1399139', 'title': 'Siege of Jerusalem (70 CE)', 'start_paragraph_id': 1, 'start_character': 236, 'end_paragraph_id': 1, 'end_character': 241, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1399139', 'title': 'Siege of Jerusalem (70 CE)', 'start_paragraph_id': 1, 'start_character': 41, 'end_paragraph_id': 1, 'end_character': 405, 'bleu_score': 0.700065642460309, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6002173898574643772}, 'section': 'Section::::Abstract.'}]}]