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 ":".
It
also
contains
both
singly
and
doubly
ionised
helium
.
It:O
also:O
contains:O
both:O
singly:O
and:O
doubly:O
ionised:O
helium:other-chemicalthing
.:O