With no explanation, label each line with "person-athlete", "organization-sportsleague", "organization-sportsteam", "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting" or "art-writtenart" preceded by ":".
Alexander
was
assigned
to
the
Alabama
Vipers
of
the
Arena
Football
League
on
December
7
,
2009
.
Alexander:person-athlete
was:O
assigned:O
to:O
the:O
Alabama:organization-sportsteam
Vipers:organization-sportsteam
of:O
the:O
Arena:organization-sportsleague
Football:organization-sportsleague
League:organization-sportsleague
on:O
December:O
7:O
,:O
2009:O
.:O