<span>The vibrations are then sent to three tiny bones in the middle ear: the malleus, incus, and stapes. These bones then amplify the sound vibrations and send them to the cochlea, a snail-shaped structure in the inner ear. The vibrations then cause the fluid inside the cochlea to ripple along the basilar membrane. This ripple stimulates the hair cells that sit on top of the basilar membrane.</span>
Answer: D.
Explanation: Structural adaptations are physical features of an organism like the bill on a bird or the fur on a bear. Other adaptations are behavioral. Behavioral adaptations are the things organisms do to survive. For example, bird calls and migration are behavioral adaptations.
Hydrosphere- oceans, lakes, glaciers, rivers, streams, and groundwater
Biosphere- all of earths living things
Atmosphere- air surrounding earth
Geosphere- earths interior, rocks, minerals, and landforms