With no explanation, label each line with "product-other", "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
The
mechanism
by
which
minoxidil
promotes
hair
growth
is
not
fully
understood
.
The:O
mechanism:O
by:O
which:O
minoxidil:product-other
promotes:O
hair:O
growth:O
is:O
not:O
fully:O
understood:O
.:O