— Do you like the English song Big Big World?

— Yes. It _____ very beautiful. [ ]

A. feels

B. hears

C. listens

D. sounds

局域网与广域网、广域网与广域网的互联是通过哪种网络设备实现的______。

A．服务器

B．网桥

C．路由器

D．交换机