多项选择题 Your ISP assigned you a full class B address space. From this, you need at least 300 sub-networks that can support at least 50 hosts each. Which of the subnet masksbelow are capable of satisfying your needs?（）

单项选择题 How many usable IP addresses can you get from a conventional Class C address?（）

多项选择题 You have a class B network with a 255.255.255.0 mask. Which of the statements below are true of this network?（）