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: Waste builds up in the blood. Blood enters the kidney. Blood passes through nephrons in the kidney. Different kinds of waste are momentarily trapped in the kidney. Cleaned blood flows out of the kidney. Filtered waste accumulates in liquid form (urine). Urine flows out of the kidney into the bladder. 

A: waste ,blood ,cleaned blood ,filtered waste ,urine 
****
Q: Air contains invisible moisture called water vapor. Excess water vapor is condensed out as water in the form of water droplets. Water droplets are carried up into the clouds. The clouds become heavy with water droplets. When the cloud is saturated. Rain will fall. 

A: water vapor ,water droplets ,cloud ,rain 
****
Q: You inhale air through your nose and mouth. The air travels down into your lungs. Oxygen from the air goes into your bloodstream. Oxygen circulates throughout the body due to the heart's pumping. Carbon dioxide travels from the blood into the lungs. Carbon dioxide travels from the lungs up the windpipe. Carbon dioxide is exhaled. 

A:
air ,oxygen ,carbon dioxide 
****