单选题 The new manager has greatly changed the company ______ he took over the position.
【正确答案】 B
【答案解析】[解析] 本题考查状语从句。本句的主句为现在完成时，从句为过去时，结合句意可知，从句应为时间状语，故正确答案为选项B。A项if引导条件状语从句，C项although引导让步状语从句，D项while可以引导让步状语从句。