iron channel

例句：

1. 1. The iron channel is essential for the construction of bridges and tunnels.
   铁制通道对于桥梁和隧道的建设至关重要。
2. 2.The engineer used a steel channel to reinforce the weak section of the wall.
   工程师使用了一个钢制通道来加固墙的薄弱部分。
3. 3. The iron channel was used to transport heavy materials through the underground passages.
   铁制通道被用来在地下通道中运输重材料。