With no explanation, label each line with "location-GPE", "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
The
second
line
was
a
gauge
contractors
'
railway
used
as
part
of
building
Maentwrog
's
(
Trawsfynydd
's
)
first
dam
in
the
1920s
.
The:O
second:O
line:O
was:O
a:O
gauge:O
contractors:O
':O
railway:O
used:O
as:O
part:O
of:O
building:O
Maentwrog:location-GPE
's:O
(:O
Trawsfynydd:location-GPE
's:O
):O
first:O
dam:O
in:O
the:O
1920s:O
.:O