With no explanation, label each line with "O", "other-astronomything", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
This
nebula
is
in
the
western
part
of
the
Perseus
molecular
cloud
and
is
a
young
region
of
very
active
star
formation
,
being
one
of
the
best-studied
objects
of
its
type
.
This:O
nebula:O
is:O
in:O
the:O
western:O
part:O
of:O
the:O
Perseus:other-astronomything
molecular:O
cloud:O
and:O
is:O
a:O
young:O
region:O
of:O
very:O
active:O
star:O
formation:O
,:O
being:O
one:O
of:O
the:O
best-studied:O
objects:O
of:O
its:O
type:O
.:O