CO2 from breathing

>>Which gets me back to my method of producing CO2.  I'm curious to know why
>>your comment about it was, "very funny".
>You meant you were serious?  It seemed like such an inefficient way of
>injecting CO2, considering the low concentration of CO2 in your breath.

I thought you were kdding too. In our CPR course, we were told
there is enough O2 in our breath to sustain another person
thus mouth to mouth recessitation.