Today many physical bookstores down with financial difficulties, inflexible management strategies and petitive pressure from online bookstores.
A. had closed
B. having closed
C. being closed
D. are closing
网友回答
A. had closed
B. having closed
C. being closed
(答案→)D. are closing
解析：答案：D 考查动词时态。句意为：由于死板的管理模式和网上书店竞争压力，如今很多实体书店因资金问题正面临着倒闭。根据语意及句中的时间状语“Today”可知，此处表示“目前正在进行和发生的动作”，因此应用现在进行时。故答案选D。