单选题 ______ one time, Manchester, New Hampshire, was the home of the most productive cotton mills in the world.
【正确答案】 B
【答案解析】[解析] 句意：曾经，新罕布什尔州的曼彻斯特是世界上最富有生产力的纺织厂之乡。at one time曾经，一度。in one time同一时间。