instruction:
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. 
question:
Warm, moist air moves from south to north. Cool, dry air moves from north to south. The air masses meet. The conditions that form are not stable because the air masses are so different. Winds are directed in a certain way because of how the masses interact. An updraft results. Winds start to form circular patterns in the updraft. A tornado can result. 
answer:
warm, moist air ,cool, dry air ,air masses ; masses ,wind ,updraft ,circular patterns ,tornado 


question:
Water vapor is in warm air. The warm air cools. The warm air expands. The water vapor in the air condenses. The water vapor forms water droplets or ice crystals. 
answer:
water vapor ,water droplets; ice crystals 


question:
A sperm meets an egg in the uterus of a woman. The sperm implants itself into the egg. The sperm and egg form a zygote on the wall of the uterus. The fetus grows and develops. The woman gives birth to a baby. The baby is raised by parents until it is able to take care of itself. The person goes out into the world and finds a job. The person meets other people and has a life. The person gets a career, and gets married. The person retires and eventually passes away. 
answer:

sperm ,egg ,zygote ,fetus ,baby ,person ,other people