Question: how long do spacers have to stay in
[{'answer': 'one to two weeks', 'provenance': [{'wikipedia_id': '2121779', 'title': 'Orthodontic spacer', 'start_paragraph_id': 3, 'start_character': 391, 'end_paragraph_id': 3, 'end_character': 407, 'bleu_score': 1.0, 'section': 'Section::::Purpose.\n'}]}, {'provenance': [{'wikipedia_id': '2121779', 'title': 'Orthodontic spacer', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 656, 'bleu_score': 0.9211712791841701, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9979796906037866877}, 'section': 'Section::::Abstract.'}]}]