a flinty heart的用法和样例：
- As hard as iron and stone, flinty heart
- Fairy tales go through a way of establishing a flinty world to realize the possible dimension, the possible narration in order to decipher the adelomorphic society.
- Obama has cast Orszag as a flinty keeper of the purse strings, but he has no intention of letting his opportunity go by.
- The meadow stones glowed white-green and a flinty wind worked over the meadow, scraped the fire low, then ruffled it into yellow silk sashes.
- During the period of French Revolution, her handicraft weathered a flinty test, when she had to make dead masks for those gentries who were sentenced to death.