单项选择题
When dividing an existing Class B network into 2 subnets of 32，766 hosts each， which of the following subnet masks should be used？（）
A.128.0.0.0 B.255.128.0.0 C.255.254.0.0 D.255.255.128.0
单项选择题 Ahostistobecomepartofahierarchicalnamingtopology.Whichofthefollowingservicesarerequired？（）
单项选择题 ToaddaTTYTerminaltoSerialport1，whichofthefollowingsetofoptionsshouldbechosen？（）
单项选择题 Whichcommandcanbeusedtomodifynetworkoptions？（）
