ceratin

例句：

1. 1. The diamond is the hardest substance known to man.
   钻石是已知的人类所知的最硬的物质。
2. 2. She wore a diamond ring on her finger.
   她戴着一枚钻石戒指在手指上。
3. 3. Diamonds are often used in jewelry and other decorative items.
   钻石经常用于珠宝和其他装饰品。