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 ":".
At
this
occasion
he
introduced
the
four
key
issues
his
programme
would
address
:
environment
,
generational
pact
,
education
,
and
public
security
.
At:O
this:O
occasion:O
he:O
introduced:O
the:O
four:O
key:O
issues:O
his:O
programme:O
would:O
address:O
::O
environment:O
,:O
generational:O
pact:O
,:O
education:O
,:O
and:O
public:O
security:O
.:O