Question: where was the first international earth summit held
[{'answer': 'Rio de Janeiro', 'provenance': [{'wikipedia_id': '324783', 'title': 'Earth Summit', 'start_paragraph_id': 1, 'start_character': 88, 'end_paragraph_id': 1, 'end_character': 102, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '324783', 'title': 'Earth Summit', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 281, 'bleu_score': 0.9418562503469401, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6057088918335630666}, 'section': 'Section::::Abstract.'}]}]