Question: where is the nucleus of a cell found
[{'answer': 'the nuclear envelope', 'provenance': [{'wikipedia_id': '6235', 'title': 'Cell nucleus', 'start_paragraph_id': 2, 'start_character': 546, 'end_paragraph_id': 2, 'end_character': 566, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '6235', 'title': 'Cell nucleus', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 857, 'bleu_score': 0.8700989081318821, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17044954720707517163}, 'section': 'Section::::Abstract.'}]}]