Question: when was the first international earth day celebrated
[{'answer': 'in 1970', 'provenance': [{'wikipedia_id': '158548', 'title': 'Earth Day', 'start_paragraph_id': 1, 'start_character': 139, 'end_paragraph_id': 1, 'end_character': 146, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '158548', 'title': 'Earth Day', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 243, 'bleu_score': 0.5697574348388831, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3962999525946415261}, 'section': 'Section::::Abstract.'}]}]