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 ":".
During
this
era
,
the
most
intense
period
of
volcanism
—
including
frequent
large
and
moderate
eruptions
—
occurred
around
6500–6400
BC
,
2250–2000
BC
,
and
AD
50–650
.
During:O
this:O
era:O
,:O
the:O
most:O
intense:O
period:O
of:O
volcanism:O
—:O
including:O
frequent:O
large:O
and:O
moderate:O
eruptions:O
—:O
occurred:O
around:O
6500–6400:O
BC:O
,:O
2250–2000:O
BC:O
,:O
and:O
AD:O
50–650:O
.:O