Come down in one continuous line is an idiom, which means that the same lineage and the same faction are handed down from generation to generation. Metaphor refers to the inheritance relationship between some thoughts, behaviors or theories.

One pulse: one pulse; Inheritance: Inheritance.

From generation to generation, some people say that wages are exhausted. The allusion is "Zhuangzi Health Master": "It is said that poverty is the salary, and fire also spreads. I don't know what it is." The interpretation is that the logs are burnt out and the fire can still be passed on.

The original explanation is that the firewood is burned out and the fire can still be passed on. Metaphor bones, immortal spirit. Later used to describe knowledge and skills passed down from generation to generation.

For example, the previous firewood has just been burned, and the next firewood has been burned, and the fire will never go out. It is a metaphor for teachers and students to teach and learn from each other from generation to generation.