Which special feature among the following is seen in frogs for...

Frogs exhibit cutaneous respiration, which is the exchange of gases across the skin. For efficient diffusion of gases, the skin must be thin, highly vascularized, and kept moist by mucus glands. A thick, dry, or non-vascular skin would prevent gaseous exchange. Frogs also lack an exoskeleton in the form of scales.

Answer: Skin is thin and moist.