With no explanation, label each line with "product-airplane", "O", "organization-other", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
It
began
its
current
active
period
in
July
1972
,
when
the
regular
Air
Force
transferred
three
squadrons
of
Republic
F-105
Thunderchiefs
to
the
reserves
.
It:O
began:O
its:O
current:O
active:O
period:O
in:O
July:O
1972:O
,:O
when:O
the:O
regular:O
Air:organization-other
Force:organization-other
transferred:O
three:O
squadrons:O
of:O
Republic:product-airplane
F-105:product-airplane
Thunderchiefs:product-airplane
to:O
the:O
reserves:O
.:O