Detailed Instructions: 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: Magma rises through surrounding rock. Gas bubbles form and expand, causing lots of pressure. This pressure pushes the magma through weak spots in the earth's surface,. Magma flows out as lava. This can happen slowly or in a huge explosion. 
A:
magma ,gas bubbles ,pressure ,lava 