Teacher: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. 
Teacher: Now, understand the problem? Solve this instance: Fault lines appear underground. The fault lines grow over time. The rocks on each side of the fault lines rub against the rocks on the other side of the fault line. The rocks put pressure on each other. The rocks break from the pressure. The breaking of the rocks releases a lot of energy. The energy causes seismic waves. The seismic waves make the earth shake. 
Student:
fault lines ,pressure ,rocks ,energy ,seismic waves 