a serious thought的用法和样例：
- A serious thought; a carefully considered reflection.
- After a serious thought, Han Jie decides to see Han Xing to offer his apology.
- Unlike his older rival, the boy was a swaggering braggart and a practical joker who had never entertained a serious thought in his empty head.
- The poor man has a serious disease of the liver.
- He received a serious wound in the battle.
- That put us at a serious disadvantage.