Question: where are the upper motor neurons that control skeletal muscles found
[{'answer': 'the precentral gyrus', 'provenance': [{'wikipedia_id': '1880464', 'title': 'Upper motor neuron', 'start_paragraph_id': 3, 'start_character': 239, 'end_paragraph_id': 3, 'end_character': 259, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1880464', 'title': 'Upper motor neuron', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 898, 'bleu_score': 0.9868845362499331, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16927395104085576987}, 'section': 'Section::::Abstract.'}]}]