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 ":".
The
airport
was
eventually
closed
at
an
unknown
date
,
and
satellite
images
show
that
the
airport
grounds
were
slowly
built
over
though
a
period
of
between
1993
and
2016
.
The:O
airport:O
was:O
eventually:O
closed:O
at:O
an:O
unknown:O
date:O
,:O
and:O
satellite:O
images:O
show:O
that:O
the:O
airport:O
grounds:O
were:O
slowly:O
built:O
over:O
though:O
a:O
period:O
of:O
between:O
1993:O
and:O
2016:O
.:O