Question: what does a bird have that no other animal has
[{'answer': 'Feathers', 'provenance': [{'wikipedia_id': '3410', 'title': 'Bird', 'start_paragraph_id': 67, 'start_character': 11, 'end_paragraph_id': 67, 'end_character': 19, 'bleu_score': 1.0, 'section': 'Section::::Anatomy and physiology.:Chromosomes.\n'}]}, {'provenance': [{'wikipedia_id': '3410', 'title': 'Bird', 'start_paragraph_id': 68, 'start_character': 0, 'end_paragraph_id': 68, 'end_character': 668, 'bleu_score': 0.9806740509884301, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17600887896713676828}, 'section': 'Section::::Anatomy and physiology.:Feathers, plumage, and scales.\n'}]}]