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: the river trent is one of the major rivers of england.

Answer: river trent

Question: valbirse is a new municipality of the administrative district of jura bernois in the canton of berne in switzerland.

Answer: valbirse

Question: joanna crussie devarona, better known as joanna kerns (born february 12, 1953) in san francisco, california) is an american actress.

Answer:
joanna kerns