With no explanation, label each line with "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport", "building-hospital" or "building-hotel" preceded by ":".
It
could
be
fitted
with
a
silencer
using
its
threaded
barrel
.
It:O
could:O
be:O
fitted:O
with:O
a:O
silencer:O
using:O
its:O
threaded:O
barrel:O
.:O