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 ":".
Cyclopentadiene
production
is
usually
not
distinguished
from
dicyclopentadiene
since
they
interconvert
.
Cyclopentadiene:O
production:O
is:O
usually:O
not:O
distinguished:O
from:O
dicyclopentadiene:O
since:O
they:O
interconvert:O
.:O