Question: who helped lewis and clark on their journey
[{'answer': 'Sacagawea', 'provenance': [{'wikipedia_id': '17615', 'title': 'Lewis and Clark Expedition', 'start_paragraph_id': 24, 'start_character': 278, 'end_paragraph_id': 24, 'end_character': 287, 'bleu_score': 1.0, 'section': 'Section::::Journey.:Departure.\n'}]}]