With no explanation, label each line with "event-attack/battle/war/militaryconflict", "O", "product-weapon", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
Several
companies
manufactured
copies
of
the
M1
carbine
after
World
War
II
,
which
varied
in
quality
.
Several:O
companies:O
manufactured:O
copies:O
of:O
the:O
M1:product-weapon
carbine:O
after:O
World:event-attack/battle/war/militaryconflict
War:event-attack/battle/war/militaryconflict
II:event-attack/battle/war/militaryconflict
,:O
which:O
varied:O
in:O
quality:O
.:O