conduit

Electrical wires are protected inside a metal conduit to prevent damage from moisture or rodents.

(Chinese) 电线被保护在金属导管内，以防止水分或啮齿动物的破坏。

The small neutral nation served as a vital conduit for diplomatic communication between the two warring powers.

(Chinese) 这个中立小国成为两个交战强权之间进行外交沟通的重要渠道。