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 ":".
There
has
therefore
been
considerable
research
interest
into
the
possible
use
of
hydrogels
in
agriculture
.
There:O
has:O
therefore:O
been:O
considerable:O
research:O
interest:O
into:O
the:O
possible:O
use:O
of:O
hydrogels:other-chemicalthing
in:O
agriculture:O
.:O