With no explanation, label each line with "O", "location-other", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
It
appears
by
the
late
1980s
that
a
Bulgarian-helmed
Balkan
Front
was
active
in
embryo
,
which
would
unfold
and
direct
the
three
armies
after
mobilization
.
It:O
appears:O
by:O
the:O
late:O
1980s:O
that:O
a:O
Bulgarian-helmed:location-other
Balkan:location-other
Front:location-other
was:O
active:O
in:O
embryo:O
,:O
which:O
would:O
unfold:O
and:O
direct:O
the:O
three:O
armies:O
after:O
mobilization:O
.:O