Question

part ii: the ear: hearing and balance
at first glance, the machinery for hearing and balance appears crude. fluids must be stirred to stimulate the receptors of the ear. sound vibrations move fluid to (1) hearing receptors, whereas gross movements of the head disturb fluids surrounding the balance organs. receptors that respond to such (2) forces are called mechanoreceptors (mek\ah-no-re-septerz)
our hearing apparatus allows us to hear an extraordinary range of sound, and our highly sensitive (3) receptors keep our nervous system continually up to date on the position and movements of the head. without this information, it would be difficult if not impossible to maintain our (4) or to know which way is up. although these two sense organs are housed together in the ear, their receptors respond to different stimuli and are activated (5) of one another.
1 independently 2 stimulate 3 physical 4 equilibrium 5 balance
1 stimulate 2 physical 3 equilibrium 4 balance 5 independently
1 balance 2 independently 3 stimulate 4 physical 5 equilibrium
1 equilibrium 2 balance 3 independently 4 stimulate 5 physical
1 physical 2 equilibrium 3 balance 4 independently 5 stimulate

Explanation:

• For blank (1), "stimulate" makes sense as sound vibrations act on hearing receptors.
• For blank (2), "physical" forces are related to the mechanical nature of the stimuli (head movements, fluid stirrings).
• For blank (3), "equilibrium" receptors are relevant for balance - related information about head position.
• For blank (4), "balance" is what we need to maintain, and it ties in with the ear's role in balance.
• For blank (5), "independently" shows that the two sets of receptors (hearing and balance) work without being directly dependent on each other.

Answer:

1. stimulate 2. physical 3. equilibrium 4. balance 5. independently