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: goldenrods are any of the about 150 species of weedy herbs that make up the genus solidago.

Answer: goldenrod


Question: painting is using colours to make art.

Answer: painting


Question: a hamburger is a type of sandwich with cooked ground meat between the two halves of a bun.

Answer:
hamburger