He commanded that all the gates when it was getting dark in case thieves came in .A. were

问题补充：

He commanded that all the gates when it was getting dark in case thieves came in .

A. were shut

B. must be shut

C. could be shut

D. be shut

答案：

A. were shut

B. must be shut

C. could be shut

(答案→)D. be shut

解析：考查虚拟语气：句意：他命令所有的门天黑的时候要关闭，以防小偷进来。主句的谓语是command，宾语从句的谓语是虚拟语气，谓语是should do，should可以省略，因为the gates和shut是被动关系，用be shut，选D。