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 ":".
Oxalate
,
the
conjugate
base
of
oxalic
acid
,
is
an
excellent
ligand
for
metal
ions
.
Oxalate:other-chemicalthing
,:O
the:O
conjugate:O
base:O
of:O
oxalic:other-chemicalthing
acid:other-chemicalthing
,:O
is:O
an:O
excellent:O
ligand:O
for:O
metal:O
ions:O
.:O