Question: what three events allowed for the formal colonization of africa in the late 1800s
[{'answer': 'Treaty of Frankfurt', 'provenance': [{'wikipedia_id': '286469', 'title': 'Scramble for Africa', 'start_paragraph_id': 64, 'start_character': 1053, 'end_paragraph_id': 64, 'end_character': 1072, 'bleu_score': 1.0, 'section': 'Section::::Colonial encounter.:Colonial consciousness and exhibitions.:Colonial lobby.\n'}]}, {'answer': 'Tonkin disaster', 'provenance': [{'wikipedia_id': '286469', 'title': 'Scramble for Africa', 'start_paragraph_id': 64, 'start_character': 1141, 'end_paragraph_id': 64, 'end_character': 1156, 'bleu_score': 1.0, 'section': 'Section::::Colonial encounter.:Colonial consciousness and exhibitions.:Colonial lobby.\n'}]}, {'answer': 'The Origins of Totalitarianism', 'provenance': [{'wikipedia_id': '286469', 'title': 'Scramble for Africa', 'start_paragraph_id': 64, 'start_character': 1189, 'end_paragraph_id': 64, 'end_character': 1219, 'bleu_score': 1.0, 'section': 'Section::::Colonial encounter.:Colonial consciousness and exhibitions.:Colonial lobby.\n'}]}, {'provenance': [{'wikipedia_id': '286469', 'title': 'Scramble for Africa', 'start_paragraph_id': 64, 'start_character': 0, 'end_paragraph_id': 64, 'end_character': 1958, 'bleu_score': 0.993431766658257, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14264611875347154946}, 'section': 'Section::::Colonial encounter.:Colonial consciousness and exhibitions.:Colonial lobby.\n'}]}]