With no explanation, label each line with "O", "product-weapon", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
Muzzle
brakes
are
simple
in
concept
,
such
as
the
one
employed
on
the
90
mm
M3
gun
used
on
the
M47
Patton
tank
.
Muzzle:O
brakes:O
are:O
simple:O
in:O
concept:O
,:O
such:O
as:O
the:O
one:O
employed:O
on:O
the:O
90:O
mm:O
M3:product-weapon
gun:O
used:O
on:O
the:O
M47:product-weapon
Patton:product-weapon
tank:O
.:O