With no explanation, label each line with "O", "other-chemicalthing", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
Polonium
alloyed
with
beryllium
provides
an
efficient
neutron
source
.
Polonium:other-chemicalthing
alloyed:O
with:O
beryllium:other-chemicalthing
provides:O
an:O
efficient:O
neutron:O
source:O
.:O