Question: principle constituent of the atmosphere of the earth
[{'answer': 'nitrous oxide', 'provenance': [{'wikipedia_id': '9228', 'title': 'Earth', 'start_paragraph_id': 50, 'start_character': 820, 'end_paragraph_id': 50, 'end_character': 833, 'bleu_score': 1.0, 'section': 'Section::::Physical characteristics.:Atmosphere.\n'}]}, {'provenance': [{'wikipedia_id': '9228', 'title': 'Earth', 'start_paragraph_id': 50, 'start_character': 0, 'end_paragraph_id': 50, 'end_character': 1234, 'bleu_score': 0.897955651479944, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2846378528483159228}, 'section': 'Section::::Physical characteristics.:Atmosphere.\n'}]}]