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]: the wisconsin river is a river in the united states.
[A]: wisconsin river


[Q]: the features of a production vehicle or production car are mass-produced identical models, offered for sale to the public.
[A]: production vehicle


[Q]: "amame" is a song by american singer selena.
[A]:
amame