该国庞大的公路和铁路网络正在不断升级。

The country's extensive road and rail ___network is constantly being upgraded.

一个可靠的电话网络对于现代通信至关重要。

A reliable telephone ___network is essential for modern communication.

他们揭露了一个横跨几大洲运作的庞大间谍网络。

They uncovered a vast spy ___network operating across several continents.