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. 
One example is below.
Q:  Magma rises from deep in the earth. The magma goes into volcanos. The volcanos pressure the magma upwards. The pressure causes the magma to push through the surface of the volcano. The lava cools. The lava forms new rock. New magma is pressured to the surface of the volcano. The volcano bursts through the rock the formed after the last eruption. 
A:  magma ,lava ,new rock 
Rationale: The entities are present in the process paragraph and they undergo state change. So, this is a positive example.
Q: Several types of gases form in the atmosphere. May come from different sources. The gases remain trapped in the atmosphere. Through the suns light the gases hold in heat and energy. Trap them in our atmosphere. The earth may become warmer this way. 
A:
several types of gases ,atmosphere ,earth ,heat ,energy 