一个hub可以看作是一个（）域，一个vlan可以看作是一个广播域。
A.冲突
B.广播
C.自相关
参考答案：A
--- Can I use the telephone on the table, sir?
--- Under no circumstances the telephone in the office for personal affairs.
A．anyone is allowed to use
B．anyone is allowed using
C．is anyone allowed to use
D．is no one allowed using
精馏塔顶温度偏高常见原因有哪些？
