信息系统受到破坏后,会对社会秩序和公共利益造成严重损害,或者对国家安全造成损害的,属信息安全等级保护的第几级?()
A.2
B.3
C.4
D.5
参考答案:B
They were made by the lovely girl.[ ]
A. to laugh
B. laugh
C. laughing
D. laughed
水池通常采用钢筋混凝土结构。( )