With no explanation, label each line with "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport", "building-hospital" or "building-hotel" preceded by ":".
Since
then
,
several
initiatives
and
plans
have
been
studied
.
Since:O
then:O
,:O
several:O
initiatives:O
and:O
plans:O
have:O
been:O
studied:O
.:O