a moral lesson的用法和样例：
- Dyer said he had taught them a moral lesson.
- An allegorical picture usually inscribed with a verse or motto presenting a moral lesson.
- An allegorical picture usually inscribed with a verseor motto presenting a moral lesson.
- We hear rather than read, for there is musicality in almost every line of his prose. We seldom learn a moral lesson because he wants us amused and relaxed.
- People can draw a moral from tales.
- A baby isn't born with a moral sense.