填空题 The appearance of the book has marked new 1 in the history of the question.
  • 1、
【正确答案】 1、era    
【答案解析】解析: The appearance(出现) of the book has marked(标志) a new era(时代) in the history of the question. 该书的出现,标志着这个问题的历史新时代