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 ":".
There
have
been
talks
about
constructing
a
fourth
line
,
but
no
one
has
done
anything
about
it
.
There:O
have:O
been:O
talks:O
about:O
constructing:O
a:O
fourth:O
line:O
,:O
but:O
no:O
one:O
has:O
done:O
anything:O
about:O
it:O
.:O