With no explanation, label each line with "O", "other-astronomything", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
The
greatest
risk
is
to
the
Earth
's
protective
ozone
layer
,
producing
effects
on
life
and
climate
.
The:O
greatest:O
risk:O
is:O
to:O
the:O
Earth:other-astronomything
's:O
protective:O
ozone:O
layer:O
,:O
producing:O
effects:O
on:O
life:O
and:O
climate:O
.:O