With no explanation, label each line with "O", "other-medical", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
As
such
,
levomethorphan
has
similar
effects
to
levorphanol
but
is
less
potent
as
it
must
be
demethylated
to
the
active
form
by
liver
enzymes
before
being
able
to
produce
its
effects
.
As:O
such:O
,:O
levomethorphan:other-medical
has:O
similar:O
effects:O
to:O
levorphanol:other-medical
but:O
is:O
less:O
potent:O
as:O
it:O
must:O
be:O
demethylated:O
to:O
the:O
active:O
form:O
by:O
liver:O
enzymes:O
before:O
being:O
able:O
to:O
produce:O
its:O
effects:O
.:O