Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.
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Question: a video projector takes a video signal and projects the corresponding image on a screen using a lens system.

Answer: video projector

Question: jeong mong-ju (, hanja:, 1337 - april 1392) was a korean goryo dynasty politician, writer, poet and thinker.

Answer: jeong mong-ju

Question: the 2019 fifa women's world cup was the eighth fifa women's world cup.

Answer:
2019 fifa women's world cup