You will be given a definition of a task first, then some input of the task.
In this task, you are given a paragraph, and your job is to generate comma-separated entities present in the given paragraph. Generate entities from a given passage in such a way that (i) they are present in the paragraph, (ii) they are non-duplicate, (iii) they underwent a state change during the process. Avoid creating entities that (i) aren't present in the process paragraph and (ii) aren't significant. 

There is a fetus in the womb. They are born and are a baby. The baby grows into a child. Puberty turns the child into an adolescent. The adolescent becomes an adult. An adult becomes an elderly person. The elderly person dies. 
Output:
fetus ,baby ,child ,adolescent ,adult ,elderly person 