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.

Q: corrosion is the breakdown of materials due to chemical reactions.

A: corrosion
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Q: the adelaide cup is a horserace, held in adelaide, south australia.

A: adelaide cup
****
Q: dell is a private company that makes laptop and desktop computers and computer accessories.

A:
dell
****