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 ":".
This
diethyl
ester
is
a
substrate
in
the
Stobbe
condensation
.
This:O
diethyl:O
ester:O
is:O
a:O
substrate:O
in:O
the:O
Stobbe:O
condensation:O
.:O