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 ":".
The
composition
of
Greek
fire
remains
a
matter
of
speculation
and
debate
,
with
various
proposals
including
combinations
of
pine
resin
,
naphtha
,
quicklime
,
calcium
phosphide
,
sulfur
,
or
niter
.
The:O
composition:O
of:O
Greek:product-weapon
fire:product-weapon
remains:O
a:O
matter:O
of:O
speculation:O
and:O
debate:O
,:O
with:O
various:O
proposals:O
including:O
combinations:O
of:O
pine:O
resin:O
,:O
naphtha:O
,:O
quicklime:O
,:O
calcium:O
phosphide:O
,:O
sulfur:O
,:O
or:O
niter:O
.:O