[Solved] Which of the following is an example of erotic touch? A) coitus B) fellatio C) kissing D) anilingus Respiratory Air Sacs: Membrane-enclosed spaces in birds that are part of the respiratory system, aiding in oxygen exchange and making flight more efficient. Three-chambered Heart: A type of heart structure found in amphibians and some reptiles, consisting of two atria and one ventricle. Amphibians: A class of cold-blooded vertebrates that includes frogs, toads, salamanders, and newts, which typically have a life cycle that includes both aquatic (larval) and terrestrial (adult) stages. Birds: Warm-blooded vertebrates that are characterized by feathers, beaks, and laying hard-shelled eggs, and they have a high metabolic rate and a lightweight skeletal system.