Humans breathe through bronchi. what structure do insects have for breathing? a. gills b. tracheae c. skin d. lungs

Insects breathe through their tracheae. Thus, the answer to the question above is letter B. Tracheae is a network of fine tubes. The air enters the insect's body through a row of holes in its abdomen. This air diffuses through to the blind - end tracheae. 

Instead of lungs, insects breathe with a network of tiny tubes called tracheae. Air enters the tubes through a row of holes along an insect's abdomen. The air then diffuses down the blind-ended tracheae. Since the biggest bugs have the longest tracheae, they should need the most oxygen to be able to breathe.
B. tracheae