floor boundary line

例句：

1. 1. The office has a beautiful wooden floor.
   办公室有一个漂亮的木质地板。
2. 2. The floor is covered in a thick layer of dust.
   地板上覆盖着一层厚厚的灰尘。
3. 3. The floor was made of polished wood.
   地板是用抛光过的木头做的。