完形填空:下面短文有5处空白,请根据短文内容为每处空白确定1个最佳选项。
In the fields of physical security and information security, access control is the selective restriction of access to a place or other resource. The actof accessing may mean consuming, entering, or using. Permission to access a resource is called authorization (授权).
An access control mechanism (71) between a user (or a process executing on behalf of a user) and system resources, such as applications, operating systems, firewalls, routers, files, and databases. The system must first authenticate(验证)a user seeking access. Typically the authentication function determines whether the user is (72) to access the system at all. Then the access control function determines if the specific requested access by this user is permitted. A security administrator maintains an authorization database that specifies what type of access to which resources is allowed for this user. The access control function consults this database to determine whether to(73)access. An auditing function monitors and keeps a record of user accesses to system resources.
In practice, a number of(74)may cooperatively share the access control function. All operating systems have at least a rudimentary(基本的), and in many cases a quite robust, access control component. Add-on security packages can add to the(75)access control capabilities of the OS. Particular applications or utilities, such as a database management system, also
incorporate access control functions. External devices, such as firewalls, can also provide access control services.
A.denied
B.permitted
C.prohibited
D.rejected
A.复杂指令系统计算机
B.超大规模集成电路
C.单指令流多数据流
D.超长指令字
A.72
B.-56
C.56
D.111
A.病毒查杀
B.端口扫描
C.QQ聊天
D.身份认证
A.WAV
B.BMP
C.MP3
D.MOV
A.流图
B.实体联系图
C.数据字典
D.软件体系结构图
采用McCabe度量法计算下图所示程序的环路复杂性为()。
A.1
B.2
C.3
D.4
A.封装
B.继承
C.覆盖
D.多态
A.序列图
B.状态图
C.通信图
D.活动图
A.分叉
B.分支
C.合并汇合
D.流
A.分支条件
B.监护表达式
C.动作名
D.流名称
A.需求分析
B.概念设计
C.逻辑设计
D.物理设计
A.大于1024的端口
B.20
C.80
D.21
A.大于1024的端口
B.20
C.80
D.21