With no explanation, label each line with "location-GPE", "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
In
1986
,
a
stretch
of
the
river
was
identified
by
the
state
of
Arizona
as
a
critical
natural
resource
.
In:O
1986:O
,:O
a:O
stretch:O
of:O
the:O
river:O
was:O
identified:O
by:O
the:O
state:O
of:O
Arizona:location-GPE
as:O
a:O
critical:O
natural:O
resource:O
.:O