value a jewel的用法和样例：
- Virtue is a jewel of great price.
- A jewel fell off her ring and she could find neither hide nor hair of it.
- He left a jewel as pledge for the borrowed horse.
- V is for virtue,virtue is a jewel of great price.
- V is virtue, virtue is a jewel of great price.
- It is a jewel worn by noble souls.