1. [单选题]Given that you have a class B IP address network range, which of the subnet masks below will allow for 100 subnets with 500 usable host addresses per subnet?
A. 255.255.0.0
B. 255.255.224.0
C. 255.255.254.0
D. 255.255.255.0
E. 255.255.255.224
2. [单选题]下列对访问控制列表的描述不正确的是（）。
A. 访问控制列表能决定数据是否可以到达某处
B. 访问控制列表可以用来定义某些过滤器
C. 一旦定义了访问控制列表，则其所规范的某些数据包就会严格被允许或拒绝
D. 访问控制列表可以应用于路由更新的过程当中
3. [单选题]Which type of cable should be used to make a connection between the Fa0/0 port on a router and the Fa0/0 port switch?
A. Rollover cable
B. Console cable
C. Crossover cable
D. Straight-through cable
E. Serial cable
4. [单选题]What is the purpose of the spanning-tree algorithm in a switched LAN?
A. To provide a monitoring mechanism for networks in switched environments.
B. To manage VLANs across multiple switches.
C. To prevent switching loops in networks with redundant switched paths.
D. To segment a network into multiple collision domains.
E. To prevent routing loops in networks.
5. [单选题]IP地址为：192.168.50.70，掩码为：255.255.255.248，则该IP地址所在子网的广播地址为（）
A. 192.168.50.32
B. 192.168.80.64
C. 192.168.50.96
D. 192.168.50.71
