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 ":".
A
wide
variety
of
catalyst
compositions
have
been
considered
,
including
metal
phosphides
.
A:O
wide:O
variety:O
of:O
catalyst:O
compositions:O
have:O
been:O
considered:O
,:O
including:O
metal:other-chemicalthing
phosphides:other-chemicalthing
.:O