Question: when did the usa join world war one
[{'answer': 'April 1917', 'provenance': [{'wikipedia_id': '25162935', 'title': 'American entry into World War I', 'start_paragraph_id': 1, 'start_character': 44, 'end_paragraph_id': 1, 'end_character': 54, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'April 6 , 1917', 'provenance': [{'wikipedia_id': '25162935', 'title': 'American entry into World War I', 'start_paragraph_id': 100, 'start_character': 3, 'end_paragraph_id': 100, 'end_character': 17, 'bleu_score': 1.0, 'section': 'Section::::Declaration of war.:Germany.\n'}]}, {'answer': 'in April 1917', 'provenance': [{'wikipedia_id': '25162935', 'title': 'American entry into World War I', 'start_paragraph_id': 1, 'start_character': 41, 'end_paragraph_id': 1, 'end_character': 54, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '25162935', 'title': 'American entry into World War I', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 685, 'bleu_score': 0.711913468653754, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1493313679884224983}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '25604889', 'title': 'United States in World War I', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['The United States declared war on Germany on April 6, 1917, more than two and a half years after World War I started. A ceasefire and Armistice was declared on November 11, 1918.', 'The United States declared war on Germany on April 6, 1917', 'The United States declared war on Germany on April 6, 1917, more than two and a half years after World War I started. A ceasefire and Armistice was declared on November 11, 1918. Before entering the war, the U.S. had remained neutral, though it had been an important supplier to Great Britain and the other Allied powers.']}}]}, {'provenance': [{'wikipedia_id': '25162935', 'title': 'American entry into World War I', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['The American entry into World War I came in April 1917, after more than two and a half years of efforts by President Woodrow Wilson to keep the United States out of the war.', 'The American entry into World War I came in April 1917', 'The American entry into World War I came in April 1917, after more than two and a half years of efforts by President Woodrow Wilson to keep the United States out of the war.']}}]}]