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 ":".
By
the
time
of
the
crash
,
the
aircraft
was
22
years
old
and
had
over
61,000
flight
hours
.
By:O
the:O
time:O
of:O
the:O
crash:O
,:O
the:O
aircraft:O
was:O
22:O
years:O
old:O
and:O
had:O
over:O
61,000:O
flight:O
hours:O
.:O