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 ":".
Carbon
monoxide
poisoning
is
the
most
common
type
of
fatal
air
poisoning
in
many
countries
.
Carbon:other-chemicalthing
monoxide:other-chemicalthing
poisoning:O
is:O
the:O
most:O
common:O
type:O
of:O
fatal:O
air:O
poisoning:O
in:O
many:O
countries:O
.:O