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. 

[EX 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. 
[EX A]: stream; river ,soil; bedrock ,gash ,dry ravine 

[EX Q]: Warm air from the surface rises into the higher cold air. The water vapor in the air is condensed. The condensed water and dust forms a cloud. Wind in the cloud bounces the water droplets around. The bouncing droplets join together. The bigger droplets get heavy. The heavy droplets fall. As they fall, they join with more moisture in the air. The droplets get larger. Rain falls. 
[EX A]: warm air ,water vapor ,condensed water ,dust ,cloud ,water droplets ; droplets ,moisture ,rain 

[EX Q]: A butterfly starts as an egg. The egg hatches. A larva emerges. The larva eats and grows. The larva sheds its skin. The larva enters a chrysalis. The pupa grows inside the chrysalis. The adult butterfly exits the chrysalis. The adult butterfly is now fully grown. The adult butterfly lays more eggs. 
[EX A]:
egg ; eggs ,larva ,pupa ,adult butterfly