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 ":".
The
by-products
(
such
as
PaOCl3
)
are
removed
by
fractional
sublimation
.
The:O
by-products:O
(:O
such:O
as:O
PaOCl3:other-chemicalthing
):O
are:O
removed:O
by:O
fractional:O
sublimation:O
.:O