小鹅卵石

例句：

1. 1. The path was paved with smooth, small pebbles.
   这条小径铺满了光滑的小鹅卵石。
2. 2. The riverbed is lined with smooth, rounded stones called cobblestones.
   河床被圆滑的鹅卵石所铺成，这些石头被称为卵石。
3. 3. The rocks were smooth and rounded, making them perfect for stepping on.
   这些岩石平滑圆润，非常适合踩踏。