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.

Example Input: A seed is in soil. The seed germinates. The plant grows roots. The plant grows out of the ground. The plant gets bigger. The plant flowers. The flower produces fruit. The fruit releases seeds. The plant dies.
Example Output: seed ,plant ,roots ,flowers ,fruit

Example Input: Air is brought in through the mouth. Passes through the lungs. And into the bronchial tissue. The carbon dioxide is removed. The lungs bring the oxygen to the rest of the body.
Example Output: air ,carbon dioxide ,oxygen

Example Input: Rain clouds travel across the sky. Rain clouds are stopped or slowed by mountains or wind. The rain clouds drop the rain. The clouds are no longer raining when or if they reach the other side of the obstacle. On the other side of the mountains or rain, there isn't much rain. The area that receives little rain develops a very different ecosystem. The area that receives little rain becomes a desert.
Example Output:
rain clouds ,rain ,clouds ,a very different ecosystem ,desert