smooth steel pipe

例句：

1. 1.The engineer used a smooth steel pipe to drill the hole.
   工程师使用一根光滑的钢管来钻那个洞。
2. 2. The smooth steel pipe was used for transportation in the tunnel.
   那根光滑的钢管被用来在隧道里运输货物。
3. 3. The smooth steel pipe is easy to install and maintain.
   这根光滑的钢管安装和保养都很容易。