Carbon monoxide is used because it is very efficiently absorbed by the lungs and is rapidly transferred to hemoglobin, the molecule in the blood that carries oxygen.
(Carbon monoxide; is used; because it is very efficiently absorbed by the lungs and is rapidly transferred to hemoglobin) (it; is very efficiently absorbed; by the lungs) (it; is rapidly transferred; to hemoglobin) (the blood; carries; oxygen)
Carbon monoxide it it the blood
is used is very efficiently absorbed is rapidly transferred carries
because it is very efficiently absorbed by the lungs and is rapidly transferred to hemoglobin
by the lungs
to hemoglobin
oxygen