Question: who sings for audrey in my fair lady
[{'answer': 'Marni Nixon', 'provenance': [{'wikipedia_id': '4836072', 'title': 'My Fair Lady (film)', 'start_paragraph_id': 68, 'start_character': 63, 'end_paragraph_id': 68, 'end_character': 74, 'bleu_score': 1.0, 'section': 'Section::::Production.:Dubbing.\n'}]}]