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 ":".
Crystals
of
calcium
oxalate
are
in
the
leaf
mesophyll
.
Crystals:O
of:O
calcium:O
oxalate:O
are:O
in:O
the:O
leaf:O
mesophyll:O
.:O