单项选择题In order to get the discounts in question, the schools or libraries have to______.
单项选择题What would eventually happen if the gap in technology access remains unclosed
单项选择题Before the early 1950's, most historians who studied pre-industrial Europe had______.
单项选择题Le Roy Ladurie is mentioned______.
单项选择题According to the passage, indictments for crime in Europe in the pre-industrial period______.