With no explanation, label each line with "location-GPE", "O", "other-medical", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
Metronidazole
began
to
be
commercially
used
in
1960
in
France
.
Metronidazole:other-medical
began:O
to:O
be:O
commercially:O
used:O
in:O
1960:O
in:O
France:location-GPE
.:O