The best speculation is that it was a mixture of carbon dioxide and water.
(The best speculation; is; that it was a mixture of carbon dioxide and water) Context(The best speculation is,List([0, 23))):(it; was; a mixture of carbon dioxide and water)
The best speculation is,List([0, 23))
The best speculation it
is was
that it was a mixture of carbon dioxide and water
a mixture of carbon dioxide and water