Question: a reference point from which all other measurements are made is called a(n)
[{'answer': 'base unit', 'provenance': [{'wikipedia_id': '19022', 'title': 'Measurement', 'start_paragraph_id': 2, 'start_character': 568, 'end_paragraph_id': 2, 'end_character': 577, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]