groove markings

例句：

1. 1. The groove marks on the wall are a reminder of the old building's history.
   墙上的凹槽标记提醒着这座老建筑的历史。
2. 2. The groove marks in the wood indicate where the saw blade has been used.
   木头上的凹槽标记表明锯片曾经被使用过。
3. 3. The groove marks on the stone floor were made by someone walking across it.
   石板地板上的凹槽标记是某人走过的痕迹。