Question: how many mg of thc to test positive
[{'answer': '50 ng / mL'}, {'provenance': [{'wikipedia_id': '35574244', 'title': 'Cannabis drug testing', 'start_paragraph_id': 12, 'start_character': 0, 'end_paragraph_id': 12, 'end_character': 808, 'bleu_score': 0.88911385179735, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7348809287028551752}, 'section': 'Section::::Testing methods.:Urine testing.\n'}]}]