With no explanation, label each line with "O", "other-astronomything", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
If
it
had
been
selected
,
``
Centaurus
``
would
have
been
the
first
mission
to
attempt
a
flyby
of
a
Centaur
.
If:O
it:O
had:O
been:O
selected:O
,:O
``:O
Centaurus:other-astronomything
``:O
would:O
have:O
been:O
the:O
first:O
mission:O
to:O
attempt:O
a:O
flyby:O
of:O
a:O
Centaur:other-astronomything
.:O