Question: the lower boundary of earth’s crust is called the
[{'answer': 'Mohorovičić discontinuity', 'provenance': [{'wikipedia_id': '145700', 'title': 'Crust (geology)', 'start_paragraph_id': 21, 'start_character': 236, 'end_paragraph_id': 21, 'end_character': 261, 'bleu_score': 1.0, 'section': "Section::::Earth's crust.:Structure.\n"}]}, {'provenance': [{'wikipedia_id': '145700', 'title': 'Crust (geology)', 'start_paragraph_id': 21, 'start_character': 0, 'end_paragraph_id': 21, 'end_character': 315, 'bleu_score': 0.96188712955549, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11447416129343012613}, 'section': "Section::::Earth's crust.:Structure.\n"}]}]