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. 

Q: 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. 

A: rain clouds ,rain ,clouds ,a very different ecosystem ,desert 
****
Q: A plant dies. Bacteria from the ground migrate to the plant material. Bacteria release enzymes onto the plant material. The enzymes break down the plant cells to simpler components. The bacteria absorb the resulting components. 

A: bacteria ,enzymes ,plant cells ,components 
****
Q: Water seeps into rocks. The water freezes and thaws. Cracks form in the rocks. Cracks also form when rocks heat up. The rocks slowly break down. 

A:
water ,rocks ,cracks 
****