This is referred to as Sleep Apnea.
<span>Refraction happens when there</span> is a bending of path of a light wave as it
passes across the boundary separating two media and the degree of bending is
determined in part by the total change in velocity as the light<span> passes from one medium to the other. In
addition, the change in speed experienced by a
wave when it changes medium can result in a number of beautiful optical effects. </span>
D. because if you think about the dna is the same as thier genetic material/genes whatever you want to call it.