While the underwater swimmer burns up oxygen through exertion, he never gets the signal from the brain &#151; the &quot;bursting lung&quot; sensation &#151; because of the low level of C02 in the lungs and blood.
(the underwater swimmer; burns up; oxygen) (he; never gets; the signal; from the brain &#151)
the underwater swimmer he
burns up never gets
oxygen
the signal from the brain &#151