With no explanation, label each line with "O", "location-other", "person-other", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
Polo
Flat
airfield
was
established
by
1921
,
when
the
aviation
pioneer
Charles
Kingsford
Smith
arrived
at
the
landing
ground
on
a
barnstorming
visit
to
the
region
.
Polo:location-other
Flat:location-other
airfield:O
was:O
established:O
by:O
1921:O
,:O
when:O
the:O
aviation:O
pioneer:O
Charles:person-other
Kingsford:person-other
Smith:person-other
arrived:O
at:O
the:O
landing:O
ground:O
on:O
a:O
barnstorming:O
visit:O
to:O
the:O
region:O
.:O