With no explanation, label each line with "location-GPE", "O", "event-attack/battle/war/militaryconflict", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
In
751
the
Chinese
were
defeated
by
an
Arab
army
in
the
Battle
of
Talas
.
In:O
751:O
the:O
Chinese:O
were:O
defeated:O
by:O
an:O
Arab:location-GPE
army:O
in:O
the:O
Battle:event-attack/battle/war/militaryconflict
of:event-attack/battle/war/militaryconflict
Talas:event-attack/battle/war/militaryconflict
.:O