machine barrel

例句：

1. 1. The machine barrel was rusted and needed to be replaced.
   机器枪筒生锈了，需要更换。
2. 2.They used a machine barrel to drill holes in the wood.
   他们使用机器枪筒在木头上钻孔。
3. 3.The machine barrel was the only thing that could penetrate the thick wall of the building.
   机器枪筒是唯一能够穿透这堵厚墙的东西。