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]: A nuclear reactor generates heat by nuclear fission. The heat created raises steam. The steam runs through turbines. The turbines generate electricity. The electricity leaves the station. 
[A]: heat ,steam ,electricity 


[Q]: He air we breathe contains oxygen and other gases. Once in the lungs, oxygen is moved into the bloodstream and carried through your body. At each cell in your body, oxygen is exchanged for a waste gas called carbon dioxide. Your bloodstream then carries this waste gas back to the lungs where it is removed from the blood stream and then exhaled. Your lungs and respiratory system automatically perform this vital process, called gas exchange. 
[A]: air ,oxygen ,carbon dioxide; waste gas 


[Q]: An organism dies. Water seeps into the remains. Minerals dissolved in the water form crystals. Crystalized minerals cause the remains to harden. The minerals form a fossil. 
[A]:
organism ,crystals; crystalized minerals; minerals ,fossil