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
airline
then
acquired
McDonnell
Douglas
DC-9-30
jetliners
,
which
replaced
the
Electras
.
The:O
airline:O
then:O
acquired:O
McDonnell:product-airplane
Douglas:product-airplane
DC-9-30:product-airplane
jetliners:product-airplane
,:O
which:O
replaced:O
the:O
Electras:product-airplane
.:O