ruby alumina

例句：

1. 1. The ruby necklace was a gift from her grandmother.
   红宝石项链是她的祖母送的礼物。
2. 2. She wore a ruby ring on her left hand.
   她左手戴着一个红宝石戒指。
3. 3. The ruby is said to be one of the most valuable gems in the world.
   据说这颗红宝石是世界上最珍贵的宝石之一。