Question: when was the first mechanical cotton picker invented
[{'answer': 'the late 1920s', 'provenance': [{'wikipedia_id': '1642993', 'title': 'Cotton picker', 'start_paragraph_id': 3, 'start_character': 297, 'end_paragraph_id': 3, 'end_character': 311, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '1642993', 'title': 'Cotton picker', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 984, 'bleu_score': 0.9662866621603431, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6009329878975317704}, 'section': 'Section::::History.\n'}]}]