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 stream or river must occur. Through erosion, the stream cuts into the soil and bedrock. Through continuous erosion, a deep gash is cut through. After many years the river may dry up. A dry ravine is left. 
[A]: stream; river ,soil; bedrock ,gash ,dry ravine 


[Q]: Fuel produces heat. Water is boiled to make steam. Steam spins turbine. Generator is turned. Makes electricity. Electricity transfers to transformers. Produces the correct voltage. 
[A]: fuel ,heat ,water ,steam ,turbine ,generator ,electricity ,voltage 


[Q]: Snow falls in an area for a very long time. The snow builds up for a very long time. The snow starts to become packed very firmly. The snow becomes something that's more like ice. Air pockets in the mass continue to grow smaller. The mass becomes solid and heavy enough to be called a glacier. The glacier moves because of gravity. 
[A]:
glacier ,snow ,mass