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 ":".
The
building
had
been
in
planning
since
1911
;
various
obstacles
,
including
World
War
I
,
held
up
progress
.
The:O
building:O
had:O
been:O
in:O
planning:O
since:O
1911:O
;:O
various:O
obstacles:O
,:O
including:O
World:event-attack/battle/war/militaryconflict
War:event-attack/battle/war/militaryconflict
I:event-attack/battle/war/militaryconflict
,:O
held:O
up:O
progress:O
.:O