Question: who directed the construction of the panama canal
[{'answer': 'David du Bose Gaillard', 'provenance': [{'wikipedia_id': '2869783', 'title': 'History of the Panama Canal', 'start_paragraph_id': 5, 'start_character': 532, 'end_paragraph_id': 5, 'end_character': 554, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2869783', 'title': 'History of the Panama Canal', 'start_paragraph_id': 80, 'start_character': 0, 'end_paragraph_id': 80, 'end_character': 465, 'bleu_score': 0.976327165973018, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13760926201918719652}, 'section': 'Section::::United States.:Summary.\n'}]}]