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 ":".
By
the
time
the
plant
was
ready
to
produce
the
simulant
the
end
of
World
War
II
was
on
the
horizon
.
By:O
the:O
time:O
the:O
plant:O
was:O
ready:O
to:O
produce:O
the:O
simulant:O
the:O
end:O
of:O
World:event-attack/battle/war/militaryconflict
War:event-attack/battle/war/militaryconflict
II:event-attack/battle/war/militaryconflict
was:O
on:O
the:O
horizon:O
.:O