Question: who sang we are the world usa for africa
[{'answer': 'supergroup', 'provenance': [{'wikipedia_id': '685793', 'title': 'We Are the World', 'start_paragraph_id': 1, 'start_character': 66, 'end_paragraph_id': 1, 'end_character': 76, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '685793', 'title': 'We Are the World', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 399, 'bleu_score': 0.748367738934214, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4393505981945858102}, 'section': 'Section::::Abstract.'}]}]