Q: The lion bit the gazelle because it had sharp teeth.
Who it is?
A: The lion

Q: The NSA sent their agents in the field to retrieve intelligence because they need people in the field to do the field work.
Who they is?
A: The NSA

Q: There is currently more work on coreference resolution than on chunking because it is a problem that is still far from being solved.
Who it is?
A:
coreference resolution