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 ":".
Arsenic
acid
is
slowly
formed
when
arsenic
pentoxide
is
dissolved
in
water
,
and
when
``
meta
''
-
or
pyroarsenic
acid
is
treated
with
cold
water
.
Arsenic:other-chemicalthing
acid:other-chemicalthing
is:O
slowly:O
formed:O
when:O
arsenic:other-chemicalthing
pentoxide:other-chemicalthing
is:O
dissolved:O
in:O
water:O
,:O
and:O
when:O
``:O
meta:O
'':O
-:O
or:O
pyroarsenic:other-chemicalthing
acid:other-chemicalthing
is:O
treated:O
with:O
cold:O
water:O
.:O