With no explanation, label each line with "O", "other-chemicalthing", "other-astronomything", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
When
the
theme
of
interplanetary
colonization
first
entered
SF
,
the
Asteroid
Belt
was
quite
low
on
the
list
of
desirable
real
estate
,
far
behind
such
planets
as
Mars
and
Venus
(
often
conceived
as
a
kind
of
paradise
planet
,
until
probes
in
the
1960s
revealed
uninhabitable
temperatures
with
a
deadly
carbon
dioxide
and
sulfur
atmosphere
under
its
clouds
)
.
When:O
the:O
theme:O
of:O
interplanetary:O
colonization:O
first:O
entered:O
SF:O
,:O
the:O
Asteroid:other-astronomything
Belt:other-astronomything
was:O
quite:O
low:O
on:O
the:O
list:O
of:O
desirable:O
real:O
estate:O
,:O
far:O
behind:O
such:O
planets:O
as:O
Mars:other-astronomything
and:O
Venus:other-astronomything
(:O
often:O
conceived:O
as:O
a:O
kind:O
of:O
paradise:O
planet:O
,:O
until:O
probes:O
in:O
the:O
1960s:O
revealed:O
uninhabitable:O
temperatures:O
with:O
a:O
deadly:O
carbon:other-chemicalthing
dioxide:other-chemicalthing
and:O
sulfur:other-chemicalthing
atmosphere:O
under:O
its:O
clouds:O
):O
.:O