Question: what are the four stages of human development
[{'answer': 'morula', 'provenance': [{'wikipedia_id': '95250', 'title': 'Development of the human body', 'start_paragraph_id': 6, 'start_character': 224, 'end_paragraph_id': 6, 'end_character': 230, 'bleu_score': 1.0, 'section': 'Section::::Before birth.:Fertilization.\n'}]}, {'answer': 'bastula'}, {'answer': 'gastrula', 'provenance': [{'wikipedia_id': '95250', 'title': 'Development of the human body', 'start_paragraph_id': 6, 'start_character': 262, 'end_paragraph_id': 6, 'end_character': 270, 'bleu_score': 1.0, 'section': 'Section::::Before birth.:Fertilization.\n'}]}, {'answer': 'neurula', 'provenance': [{'wikipedia_id': '95250', 'title': 'Development of the human body', 'start_paragraph_id': 6, 'start_character': 286, 'end_paragraph_id': 6, 'end_character': 293, 'bleu_score': 1.0, 'section': 'Section::::Before birth.:Fertilization.\n'}]}, {'provenance': [{'wikipedia_id': '95250', 'title': 'Development of the human body', 'start_paragraph_id': 6, 'start_character': 68, 'end_paragraph_id': 6, 'end_character': 1284, 'bleu_score': 0.905377998797907, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7350974191493784857}, 'section': 'Section::::Before birth.:Fertilization.\n'}]}]