Question

answer a qbhkjkuestion

Answer 1

Answer:

the fact or phenomenon of light, radio waves, etc. being deflected in passing obliquely through the interface between one medium and another or through a medium of varying density.

change in direction of propagation of any wave as a result of its travelling at different speeds at different points along the wave front.

measurement of the focusing characteristics of an eye or eyes.

Answer 2

Answer:

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