Question: how many versions of the ipad air are there
[{'answer': 'eight'}, {'provenance': [{'wikipedia_id': '25970423', 'title': 'IPad', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 1124, 'bleu_score': 0.866096523687217, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3906123374009726259}, 'section': 'Section::::Abstract.'}]}]