Question: commonly used as a preservative for tissue specimens
[{'answer': 'formaldehyde', 'provenance': [{'wikipedia_id': '8156507', 'title': 'Fixation (histology)', 'start_paragraph_id': 22, 'start_character': 48, 'end_paragraph_id': 22, 'end_character': 60, 'bleu_score': 1.0, 'section': 'Section::::Chemical fixation.:Crosslinking fixatives – aldehydes.\n'}]}, {'provenance': [{'wikipedia_id': '8156507', 'title': 'Fixation (histology)', 'start_paragraph_id': 22, 'start_character': 0, 'end_paragraph_id': 22, 'end_character': 883, 'bleu_score': 0.7197401591854291, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12963448075322951990}, 'section': 'Section::::Chemical fixation.:Crosslinking fixatives – aldehydes.\n'}]}]