They urged that the library open during the vacation.A. must be keptB. is keptC. would be

问题补充：

They urged that the library open during the vacation.

A. must be kept

B. is kept

C. would be kept

D. be kept

答案：

(答案→)A. must be kept

B. is kept

C. would be kept

D. be kept

解析：

此题考查含有情态动词的被动语态的基本结构，情态动词+be+done。此题的含义表示他们强烈要求在假期开放图书馆。