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 ":".
Therefore
the
forming
of
a
pair-bonding
will
commonly
occur
in
the
first
winter
.
Therefore:O
the:O
forming:O
of:O
a:O
pair-bonding:O
will:O
commonly:O
occur:O
in:O
the:O
first:O
winter:O
.:O