With no explanation, label each line with "product-airplane", "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
The
Me-262
twin
jet
and
Me-163
single
rocket
engine
aircraft
first
appeared
in
small
numbers
at
the
end
of
1944
.
The:O
Me-262:product-airplane
twin:O
jet:O
and:O
Me-163:product-airplane
single:O
rocket:O
engine:O
aircraft:O
first:O
appeared:O
in:O
small:O
numbers:O
at:O
the:O
end:O
of:O
1944:O
.:O