单项选择题 You work as network consultant. Your customer, TestKing Inc, has a class C network license. TestKing wants you to subnet the network to provide a separate subnet for each of its 5 departments. Each subnet must support at least 24 hosts. Which network mask should you use?（）

单项选择题 If an Ethernet port on router was assigned an IP address of 172.16.112.1/20, what is the maximum number of hosts allowed on this subnet?（）

多项选择题 Which of the following IP addresses fall into the CIDR block of 115.54.4.0/22? （）