All of the following are types of symbiotic relationships except for

a. competitive exclusion.
b. parasitism.
c. commensalism.
d. mutualism.
answer is a

stress fractures occur largely in the feet and legs and are common in sports that require repetitive impact, primarily running/jumping sports such as gymnastics or track and field.

answer'(basidium)the spore--bearing structure of a basidiomycete is called a basidiocarp; ///