Answer:
chemicals
Explanation:
The nose and the tongue are two of the five sensory organs (others being skin, eyes, ears). These organs contain certain cellular structures called SENSORY RECEPTORS, which respond to different stimulus in the environment.
Nose and tongue are two organs that possess a type of sensory receptor called CHEMORECEPTORS. Chemoreceptors are receptors that respond to chemical stimuli. In other words, the receptors in the nose and tongue are stimulated by chemical substances e.g. food chemicals for TONGUE, chemicals in air for NOSE.
The term is nitrogen fixation.
It should be 2, but I'm not exactly sure
