Question: when does the acrosome reaction occur in sperm
[{'answer': 'as it approaches the egg', 'provenance': [{'wikipedia_id': '443228', 'title': 'Acrosome reaction', 'start_paragraph_id': 1, 'start_character': 445, 'end_paragraph_id': 1, 'end_character': 469, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '443228', 'title': 'Acrosome reaction', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 552, 'bleu_score': 0.9470575400422261, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8974864465104714066}, 'section': 'Section::::Abstract.'}]}]