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.

[EX Q]: the duke lemur center is an 85 acre sanctuary for several species of lemurs and lorises.
[EX A]: duke lemur center

[EX Q]: the viverridae is a family of small to medium-sized mammals, the viverrids.
[EX A]: viverridae

[EX Q]: dmitri radchenko (born 2 december 1970) is a former russian football player.
[EX A]:
dmitri radchenko