In this task, You are given an open-domain question that can be answered based on factual information. Your task is to provide \*short\* answer (in a few words only) for the given question. The short answer can be one or more entities or it can also be boolean \*yes\* or \*no\*.

Q: who sings how do u like me now

A: Toby Keith
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Q: where does the white house get their christmas tree

A: various growers nationwide
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Q: number of years required for the world's population to double

A:
by the year 2100
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