1. Identify pupil in this diagram.   D   B   A   C   Hint Hint       2. Identify iris in this diagram.   C   D   B   A   Hint       3. Viscous fluid filled in the space behind the lens:   Vitreous humor   Both   Aqueous humor   Half-n-half Clue   4. True or false: The end organs (receptors) of smell are known as olfactory neurons.   True   False   Hint       5. Thin watery fluid, which is filled in the space just behind the cornea   Vitreous humor   Gel   Aqueous humor   Half-n-half Clue   6. Identify the ear ossicle "A" in this diagram.   Stapes   Incus   Malleus   Hint       7. Coiled structure located in the inner ear is known as _______.   Semicircular canal   Helico trema   Cochlea   Eustachian tube   Half-n-half Clue