Question: who sings the song nothing's gonna stop us now
[{'answer': 'Grace Slick', 'provenance': [{'wikipedia_id': '5472954', 'title': "Nothing's Gonna Stop Us Now", 'start_paragraph_id': 1, 'start_character': 197, 'end_paragraph_id': 1, 'end_character': 208, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Mickey Thomas', 'provenance': [{'wikipedia_id': '5472954', 'title': "Nothing's Gonna Stop Us Now", 'start_paragraph_id': 1, 'start_character': 213, 'end_paragraph_id': 1, 'end_character': 226, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '5472954', 'title': "Nothing's Gonna Stop Us Now", 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 790, 'bleu_score': 0.8328115824105411, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7331157055883291198}, 'section': 'Section::::Abstract.'}]}]