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 ":".
His
research
has
questioned
whether
anti-cancer
drugs
could
be
acting
through
alternate
mechanisms
.
His:O
research:O
has:O
questioned:O
whether:O
anti-cancer:O
drugs:O
could:O
be:O
acting:O
through:O
alternate:O
mechanisms:O
.:O