As additional heat is added to the liquid, it is used to raise the T of the substance to its boiling point.
(additional heat; is added; to the liquid) (it; is used; to raise the T of the substance to its boiling point) (it; to raise; the T of the substance to its boiling point)
additional heat it it
is added is used to raise
to the liquid
to raise the T of the substance to its boiling point
the T of the substance to its boiling point