Question: when was chlorine first used in drinking water
[{'answer': '1893', 'provenance': [{'wikipedia_id': '38840679', 'title': 'Water chlorination', 'start_paragraph_id': 3, 'start_character': 288, 'end_paragraph_id': 3, 'end_character': 292, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '38840679', 'title': 'Water chlorination', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 420, 'bleu_score': 0.972407137066537, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1866712223993478867}, 'section': 'Section::::History.\n'}]}]