unfired tube

例句：

1. 1. The construction crew used unfired tubes to reinforce the foundation.
   建筑工人使用未烧制的管子来加固地基。
2. 2.The engineer recommended using unfired tubes for the piping system.
   工程师建议使用未烧制的管子来铺设管道系统。
3. 3.The unfired tubes were installed in the walls to improve their strength and durability.
   在墙壁中安装了未烧制的管子，以增强其强度和耐久性。