They demanded that the library open to students during the vacation.A. should keepB. was

问题补充：

They demanded that the library open to students during the vacation.

A. should keep

B. was kept

C. would be kept

D. be kept

答案：

A. should keep

B. was kept

C. would be kept

(答案→)D. be kept

解析：考查虚拟语气：主句的动词是demand，从句的谓语用（should） do表示虚拟语气，the library和keep是被动关系，用be kept，句意：他们要求假期图书馆向学生开放，选D。