Producers make up what part of the food chain

would be the second part, plants.

energy (sun) -> producers -> consumers -> decomposers

Producers make up the autotrophs or the first level of a food chain

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.

the wires in the toaster turning red and the toast crisping and turning brown