With no explanation, label each line with "O", "other-chemicalthing", "other-biologything", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
In
biogas
plants
,
propionic
acid
is
a
common
intermediate
product
,
which
is
formed
by
fermentation
with
propionic
acid
bacteria
.
In:O
biogas:O
plants:O
,:O
propionic:other-chemicalthing
acid:other-chemicalthing
is:O
a:O
common:O
intermediate:O
product:O
,:O
which:O
is:O
formed:O
by:O
fermentation:O
with:O
propionic:other-biologything
acid:other-biologything
bacteria:other-biologything
.:O