With no explanation, label each line with "O", "organization-sportsleague", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
The
tournament
was
classified
as
a
Tier
II
event
on
the
2007
WTA
Tour
.
The:O
tournament:O
was:O
classified:O
as:O
a:O
Tier:O
II:O
event:O
on:O
the:O
2007:O
WTA:organization-sportsleague
Tour:organization-sportsleague
.:O