With no explanation, label each line with "O", "other-chemicalthing", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
This
causes
the
anti-terminator
loop
to
form
and
the
tryptophan
operon
to
be
transcribed
.
This:O
causes:O
the:O
anti-terminator:O
loop:O
to:O
form:O
and:O
the:O
tryptophan:other-chemicalthing
operon:O
to:O
be:O
transcribed:O
.:O