ring cell

例句：

1. 1. This ring cell is the key to unlocking the door.
   这个环形细胞是打开门的关键。
2. 2. The ring cell is responsible for maintaining the integrity of the blood vessel wall.
   环形细胞负责保持血管壁的完整性。
3. 3. The ring cell is a type of specialized epithelial cell that lines the inner surface of the ear.
   环形细胞是一种特化的上皮细胞，位于耳内表面。