the hollow organ for cleaning up the wastes

例句：

1. 1. The tree ishollow, so it can't supportthe weight of the branches.
   这棵树是空心的，所以它不能支撑树枝的重量。
2. 2. The room was hollow and echoedwith the sound of our footsteps.
   房间是空的，我们的脚步声在里面回响。
3. 3. The hole in the wallwas hollow, and I could see myreflection in it.
   墙上的洞是空的，我能在它里面看到自己的倒影。