With no explanation, label each line with "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport", "building-hospital" or "building-hotel" preceded by ":".
Spacebus
designations
were
not
applied
retrospectively
to
satellites
which
had
already
been
launched
.
Spacebus:O
designations:O
were:O
not:O
applied:O
retrospectively:O
to:O
satellites:O
which:O
had:O
already:O
been:O
launched:O
.:O