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 ":".
In
1947
,
trucks
and
buses
were
pressed
into
service
as
bookmobiles
.
In:O
1947:O
,:O
trucks:O
and:O
buses:O
were:O
pressed:O
into:O
service:O
as:O
bookmobiles:O
.:O