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 ":".
His
mother
and
father
both
appeared
in
the
witness
box
and
his
mother
broke
down
in
the
court
.
His:O
mother:O
and:O
father:O
both:O
appeared:O
in:O
the:O
witness:O
box:O
and:O
his:O
mother:O
broke:O
down:O
in:O
the:O
court:O
.:O