Question: which crops were covered by the green revolution in the 1960s
[{'answer': 'wheat', 'provenance': [{'wikipedia_id': '14101118', 'title': 'Green Revolution in India', 'start_paragraph_id': 2, 'start_character': 251, 'end_paragraph_id': 2, 'end_character': 256, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'maize'}, {'answer': 'bajra'}]