With no explanation, label each line with "O", "event-disaster", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
The
analysis
of
the
effect
of
Northridge
earthquake
on
behavior
of
structures
has
been
investigated
by
many
researchers
.
The:O
analysis:O
of:O
the:O
effect:O
of:O
Northridge:event-disaster
earthquake:event-disaster
on:O
behavior:O
of:O
structures:O
has:O
been:O
investigated:O
by:O
many:O
researchers:O
.:O