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: You find an empty ice cube tray. You fill the tray with warm water. You carefully place the tray on an even surface in a freezer that is at least 32 degree Farhenheit, the freezing point of water. The water begins to get colder until it starts to freeze solid. The water expands as it freezes, one of the few liquids that has greater volume as a solid. Because you used warm water, the gasses in the water had evaporated out, so you will have nice clear ice cubes without cracks from the trapped gasses. 
Student:
warm water ,ice cubes 