在网络层上实现多个网络互联的设备是（）。
参考答案：路由器
— I think the whole class is going on a field trip next Friday.
— I'm not sure. _____ has paid the transportation fee. [ ]
A. Not everyone
B. No one
C. None of them
D. Neither of us
城市房屋拆迁估价计价货币是以人民币为计价的货币，精确到元。( )
