With no explanation, label each line with "O", "other-chemicalthing", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
Phenols
undergo
esterification
.
Phenols:other-chemicalthing
undergo:O
esterification:O
.:O