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: escape velocity is the initial speed that something would need to completely escape the gravity of a large body, like a star or a planet (such as the earth), by mere inertia.

A: escape velocity
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Q: sir philip anthony hopkins cbe (born 31 december 1937) is a welsh actor of movies, theater and television.

A: anthony hopkins
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Q: wawiriya burton is an australian aboriginal artist.

A:
wawiriya burton
****