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. 
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Question: A plant dies and withers. The dead plant starts to draw microbes. The microbes break down the material. Forms decay. The resulting material disappears. The plant becomes one with the soil. 

Answer: plant ; material ,microbes 


Question: Coal is loaded into the firebox. The boiler produces steam under high pressure. The steam generated in the boiler flows down into a cylinder. Just ahead of the wheels, pushing a tight-fitting plunger, the piston. The piston is connected to one or more of the locomotive's wheels through a kind of arm-elbow-shoulder joint called a crank and connecting rod. As the piston pushes, the crank and connecting rod turn the locomotive's wheels and power the train along. An outlet valve opens and the piston pushes the steam back through the cylinder and out up the locomotive's chimney. 

Answer: coal ,steam 


Question: Sound enters the ears of a person. The sound hits a drum that is inside the ear. The drum inside the ear converts the sound to electrical impulses. The electrical impulses are sent to the brain. The brain can decode the impulses into sound. 

Answer:
sound ,electrical impulses ,sound