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. 

Ex Input:
You receive a vaccination through an injection or a nasal spray. The vaccine contains a weakened version of the virus or bacteria responsible for the disease. The body's immune system reacts to the virus or bacteria. The immune system creates antibodies to fight the virus or bacteria. The antibodies remain in the body. The antibodies are ready to fight the disease if the person is infected with the disease. 

Ex Output:
virus or bacteria ,antibodies 


Ex Input:
You take some paper. The writing tools. You write a message describing what's on your mind. You put the letter into an envelope. You take the letter to the post office. Send it to its recipient. 

Ex Output:
paper ,writing tool ,message ,letter 


Ex Input:
When water freezes it becomes 10% bigger, or takes up 10% more space. As water expands it puts great pressure on the walls of anything containing it, including any rocks which happen to be surrounding it. The force of the pressure exerted on the rock surrounding it is enough to wedge the walls of the crack farther apart, thus expanding and deepening the crack. Clay expends when wet like ice does. This causes rock to break apart. Some plants like mosses and lichens are capable of growing without soil on bare rock. When they do this their roots penetrate pores and crevices and cause rocks to split apart as the roots force their way down through the rocks. 

Ex Output:

crack ,rock