With no explanation, label each line with "O", "event-attack/battle/war/militaryconflict", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
At
the
end
of
World
War
I
,
Douglas
retired
from
engineering
to
promote
his
reform
ideas
full-time
,
which
he
would
do
for
the
rest
of
his
life
.
At:O
the:O
end:O
of:O
World:event-attack/battle/war/militaryconflict
War:event-attack/battle/war/militaryconflict
I:event-attack/battle/war/militaryconflict
,:O
Douglas:O
retired:O
from:O
engineering:O
to:O
promote:O
his:O
reform:O
ideas:O
full-time:O
,:O
which:O
he:O
would:O
do:O
for:O
the:O
rest:O
of:O
his:O
life:O
.:O