With no explanation, label each line with "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport", "building-hospital" or "building-hotel" preceded by ":".
Since
the
pilot
's
open
cockpit
was
well
forward
,
it
was
lower
than
that
of
the
gunner
in
the
rear
cockpit
making
forward
fire
safer
.
Since:O
the:O
pilot:O
's:O
open:O
cockpit:O
was:O
well:O
forward:O
,:O
it:O
was:O
lower:O
than:O
that:O
of:O
the:O
gunner:O
in:O
the:O
rear:O
cockpit:O
making:O
forward:O
fire:O
safer:O
.:O