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 ":".
It
was
discovered
in
1955
by
an
American
astronomer
Albert
George
Wilson
.
It:O
was:O
discovered:O
in:O
1955:O
by:O
an:O
American:O
astronomer:O
Albert:O
George:O
Wilson:O
.:O