Question: when did the vikings arrive in north america
[{'answer': 'in the 980s', 'provenance': [{'wikipedia_id': '295764', 'title': 'Norse colonization of North America', 'start_paragraph_id': 4, 'start_character': 84, 'end_paragraph_id': 4, 'end_character': 95, 'bleu_score': 1.0, 'section': 'Section::::Norse Greenland.\n'}]}, {'provenance': [{'wikipedia_id': '295764', 'title': 'Norse colonization of North America', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 439, 'bleu_score': 0.9720210313175831, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9412528970145074451}, 'section': 'Section::::Norse Greenland.\n'}]}]