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 ":".
The
electrons
from
the
aluminium
reduce
mercuric
Hg2+
ion
to
metallic
mercury
.
The:O
electrons:O
from:O
the:O
aluminium:O
reduce:O
mercuric:O
Hg2+:other-chemicalthing
ion:O
to:O
metallic:O
mercury:O
.:O