tuckstone

例句：

1. 1. The path was lined with smooth tuckstones, making it easy to walk on.
   小径两旁铺满了光滑的卵石，走起来很舒适。
2. 2. She carefully picked up the large tuckstone and placed it in her basket.
   她小心翼翼地捡起了这块大卵石，放进了她的篮子里。
3. 3.The old house had been built on a hillside, surrounded by smooth tuckstone walls.
   这座老房子建在山坡上，四周都是平滑的卵石墙。