With no explanation, label each line with "O", "event-attack/battle/war/militaryconflict", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
A
turning
point
was
the
Battle
of
Talas
of
751
.
A:O
turning:O
point:O
was:O
the:O
Battle:event-attack/battle/war/militaryconflict
of:event-attack/battle/war/militaryconflict
Talas:event-attack/battle/war/militaryconflict
of:O
751:O
.:O