With no explanation, label each line with "O", "other-chemicalthing", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
The
primary
chemical
precursor
to
TCA
is
TCP
(
2,4,6-trichlorophenol
)
,
an
anti-microbial
agent
used
in
processing
wood
.
The:O
primary:O
chemical:O
precursor:O
to:O
TCA:other-chemicalthing
is:O
TCP:other-chemicalthing
(:O
2,4,6-trichlorophenol:O
):O
,:O
an:O
anti-microbial:O
agent:O
used:O
in:O
processing:O
wood:O
.:O