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: Air rises. Rising air cools. Water vapor forms. Water vapor condenses. Clouds form. 
Student:
air ; rising air ,water vapor ,clouds 