notches

例句：

1. 1. The car has several notches on its hood.
   这辆车的引擎盖上有几个凹口。
2. 2. The tree has many notches along its trunk.
   这棵树的树干上有很多槽口。
3. 3. The old clock had a series of notches for marking the hours.
   旧时钟有一系列槽口用来标记小时。