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 ":".
Other
compounds
include
titanium
tetrachloride
(
TiCl4
)
,
a
component
of
smoke
screens
and
catalysts
;
and
titanium
trichloride
(
TiCl3
)
,
which
is
used
as
a
catalyst
in
the
production
of
polypropylene
.
Other:O
compounds:O
include:O
titanium:other-chemicalthing
tetrachloride:other-chemicalthing
(:O
TiCl4:other-chemicalthing
):O
,:O
a:O
component:O
of:O
smoke:O
screens:O
and:O
catalysts:O
;:O
and:O
titanium:other-chemicalthing
trichloride:other-chemicalthing
(:O
TiCl3:other-chemicalthing
):O
,:O
which:O
is:O
used:O
as:O
a:O
catalyst:O
in:O
the:O
production:O
of:O
polypropylene:other-chemicalthing
.:O