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
has
been
called
the
``
greenest
''
laboratory
facility
in
the
United
States
It:O
has:O
been:O
called:O
the:O
``:O
greenest:O
'':O
laboratory:O
facility:O
in:O
the:O
United:O
States:O