Chang gets paid a $50 bonus for every 100 pairs of shoes that he sells. chang is being reinforced on a schedule of reinforcement.

i think that d. wind is the answer.   i missed the question when i answered a. currents.

the answer is: trichonympha lives in the gut of termites and digests cellulose eaten by the termite.

this is an example of a symbiotic association of a protozoan with its mode of association.

hope i

-lavira: )