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
television
has
been
one
of
the
most
important
media
for
marketing
toys
.
Since:O
then:O
television:O
has:O
been:O
one:O
of:O
the:O
most:O
important:O
media:O
for:O
marketing:O
toys:O
.:O