Question: where did the vietnam war mainly take place
[{'answer': 'Vietnam', 'provenance': [{'wikipedia_id': '32611', 'title': 'Vietnam War', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 7, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Laos', 'provenance': [{'wikipedia_id': '32611', 'title': 'Vietnam War', 'start_paragraph_id': 1, 'start_character': 171, 'end_paragraph_id': 1, 'end_character': 175, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Cambodia', 'provenance': [{'wikipedia_id': '32611', 'title': 'Vietnam War', 'start_paragraph_id': 1, 'start_character': 181, 'end_paragraph_id': 1, 'end_character': 189, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '32611', 'title': 'Vietnam War', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 814, 'bleu_score': 0.54287254165989, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10870480877448161901}, 'section': 'Section::::Abstract.'}]}]