Question: who reached the bottom of the mariana trench
[{'answer': 'Canadian film director James Cameron', 'provenance': [{'wikipedia_id': '19036', 'title': 'Mariana Trench', 'start_paragraph_id': 22, 'start_character': 171, 'end_paragraph_id': 22, 'end_character': 207, 'bleu_score': 1.0, 'section': 'Section::::Research history.:Descents.\n'}]}, {'provenance': [{'wikipedia_id': '19036', 'title': 'Mariana Trench', 'start_paragraph_id': 22, 'start_character': 0, 'end_paragraph_id': 22, 'end_character': 350, 'bleu_score': 0.819885809593985, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5487273960895877501}, 'section': 'Section::::Research history.:Descents.\n'}]}]