Question: when did the us begin sending large numbers of troops to join world war i in europe
[{'answer': 'June 1917', 'provenance': [{'wikipedia_id': '21001269', 'title': 'History of the United States Army', 'start_paragraph_id': 72, 'start_character': 201, 'end_paragraph_id': 72, 'end_character': 210, 'bleu_score': 1.0, 'section': 'Section::::Twentieth century.:World War I.\n'}]}, {'provenance': [{'wikipedia_id': '21001269', 'title': 'History of the United States Army', 'start_paragraph_id': 72, 'start_character': 0, 'end_paragraph_id': 72, 'end_character': 441, 'bleu_score': 0.8183654702463241, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11151043514964752393}, 'section': 'Section::::Twentieth century.:World War I.\n'}]}]