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
synthesis
of
diethyl
ether
by
a
reaction
between
ethanol
and
sulfuric
acid
has
been
known
since
the
13th
century
.
The:O
synthesis:O
of:O
diethyl:other-chemicalthing
ether:other-chemicalthing
by:O
a:O
reaction:O
between:O
ethanol:other-chemicalthing
and:O
sulfuric:other-chemicalthing
acid:other-chemicalthing
has:O
been:O
known:O
since:O
the:O
13th:O
century:O
.:O