step cover

例句：

1. 1.The steps on the stairs were covered in a layer of dust.
   楼梯上的台阶上积了一层灰尘。
2. 2. The new step cover made the old one look even more worn out.
   新的台阶覆盖物让旧的看起来更破旧了。
3. 3. The builders had to step over the old step cover to get to the other side of the building.
   建筑工人不得不跳过旧的台阶覆盖物才能到达建筑物的另一侧。