Question: what is the job of the us ambassador
[{'answer': 'an official envoy', 'provenance': [{'wikipedia_id': '68651', 'title': 'Ambassador', 'start_paragraph_id': 1, 'start_character': 17, 'end_paragraph_id': 1, 'end_character': 34, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '68651', 'title': 'Ambassador', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 502, 'bleu_score': 0.9738505480425671, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12013632671179277152}, 'section': 'Section::::Abstract.'}]}]