With no explanation, label each line with "O", "organization-other", "person-scholar", "product-weapon", "event-attack/battle/war/militaryconflict", "art-broadcastprogram", "art-film", "art-music", "art-other" or "art-painting" preceded by ":".
According
to
historians
Yoshiaki
Yoshimi
and
Kentaro
Awaya
,
during
the
Second
Sino-Japanese
War
,
gas
weapons
,
such
as
tear
gas
,
were
used
only
sporadically
in
1937
,
but
in
early
1938
the
Imperial
Japanese
Army
began
full-scale
use
of
phosgene
,
chlorine
,
Lewisite
and
nausea
gas
(
red
)
,
and
from
mid-1939
,
mustard
gas
(
yellow
)
was
used
against
both
Kuomintang
and
Communist
Chinese
troops
.
According:O
to:O
historians:O
Yoshiaki:person-scholar
Yoshimi:person-scholar
and:O
Kentaro:person-scholar
Awaya:person-scholar
,:O
during:O
the:O
Second:event-attack/battle/war/militaryconflict
Sino-Japanese:event-attack/battle/war/militaryconflict
War:event-attack/battle/war/militaryconflict
,:O
gas:O
weapons:O
,:O
such:O
as:O
tear:product-weapon
gas:product-weapon
,:O
were:O
used:O
only:O
sporadically:O
in:O
1937:O
,:O
but:O
in:O
early:O
1938:O
the:O
Imperial:organization-other
Japanese:organization-other
Army:organization-other
began:O
full-scale:O
use:O
of:O
phosgene:product-weapon
,:O
chlorine:product-weapon
,:O
Lewisite:product-weapon
and:O
nausea:product-weapon
gas:product-weapon
(:product-weapon
red:product-weapon
):product-weapon
,:O
and:O
from:O
mid-1939:O
,:O
mustard:product-weapon
gas:product-weapon
(:product-weapon
yellow:product-weapon
):product-weapon
was:O
used:O
against:O
both:O
Kuomintang:organization-other
and:O
Communist:organization-other
Chinese:organization-other
troops:O
.:O