a petrified expression的用法和样例：
- A statue found in an ancient ruin is actually a petrified spell caster from a bygone era.
- "In feathered hats that were once the rage, she resembles a petrified parakeet from the Jurassic age.
- Scientists in Germany have announced the discovery of a petrified hoard of 17-million-year-old nuts they say form the oldest known cache of stored food.
- He always shows a doleful expression.