Question: britain and france declare war on germany when
[{'answer': 'after German forces invaded Poland', 'provenance': [{'wikipedia_id': '42682692', 'title': 'British and French declaration of war on Germany', 'start_paragraph_id': 1, 'start_character': 87, 'end_paragraph_id': 1, 'end_character': 121, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '42682692', 'title': 'British and French declaration of war on Germany', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 307, 'bleu_score': 0.959574895300321, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6325289738053345575}, 'section': 'Section::::Abstract.'}]}]