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.

The inner portion of the ring is formed during rapid spring growth. The tree's growth slows as the seasons change. The ring's outer growth is more dense. The growth of the tree pushes out the bark of the tree. The tree stops growing quickly in the winter. This seasonal "pause" in growth results in distinct rings in certain tree types.
bark ,inner portion of the ring