With no explanation, label each line with "O", "event-sportsevent", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
Since
1992
the
American
Derby
has
been
run
on
turf
.
Since:O
1992:O
the:O
American:event-sportsevent
Derby:event-sportsevent
has:O
been:O
run:O
on:O
turf:O
.:O